How to Calculate Cost per Gram of Protein

The cheapest food per kilogram is not necessarily the cheapest source of protein.

A food might cost very little but contain relatively little protein.

Another food might cost more at checkout but provide much more protein per package.

To compare them, I calculate:

For example, suppose a yogurt container costs:

$5.40

It contains:

6 servings

Each serving provides:

17 g protein

First calculate total protein:

Then:

That means the yogurt costs approximately:

$0.053 per gram of protein

or:

5.3 cents per gram of protein

This calculation is useful because it separates the price of the food from the amount of protein the food actually provides.

The basic formula

Use:

That is the entire calculation.

The main challenge is determining the correct total protein amount.

For packaged foods, you can usually calculate it from:

protein per serving × servings per container

FDA explains that the Nutrition Facts label provides nutrition information based on the stated serving size and shows the number of servings per container. FDA also notes that serving sizes are standardized reference amounts based on typical consumption, not individualized recommendations for how much someone should eat.

So:

Then:

Example with a packaged food

Suppose cottage cheese costs:

$4.80

The label says:

4 servings per container

and:

14 g protein per serving

Total protein:

Cost per gram:

$4.80 ÷ 56 ≈ $0.0857

So the food costs approximately:

8.6 cents per gram of protein

The exact result will depend on the product’s actual price and label.

Why price per gram of food is different

Suppose two foods cost exactly:

$0.50 per 100 g of food

They appear equally expensive by weight.

But imagine:

Food A

10 g protein per 100 g

Food B

25 g protein per 100 g

Food B supplies:

2.5 times as much protein

for the same amount of food and the same price.

That is why:

price per gram of food

and:

price per gram of protein

answer different questions.

NIST describes unit pricing as a useful way to compare the cost of equivalent quantities of products, such as price per ounce or another standard unit.

Protein-cost calculations add another layer by asking how much of a particular nutrient that purchase provides.

Unit price versus protein price

Use unit price when you want to know:

Which package is cheaper per gram of food?

Use protein cost when you want to know:

Which product gives me protein for less money?

For example:

Product A

500 g $5 20 g protein per 100 g

Food unit price:

$1 per 100 g

Total protein:

Protein cost:

Product B

500 g $4 12 g protein per 100 g

Food unit price:

$0.80 per 100 g

B is cheaper by food weight.

But total protein:

Protein cost:

$4 ÷ 60 ≈ $0.0667 per gram

So:

Product B is cheaper per gram of food.

But:

Product A is cheaper per gram of protein.

That distinction is exactly why protein-cost calculations are useful.

Method 1: Use servings per container

This is easiest for packaged products.

You need three numbers:

Package price

Protein per serving

Servings per container

Formula:

Then:

Example

Price:

$6.50

Protein:

15 g per serving

Servings:

5

Total protein:

Cost per gram:

$6.50 ÷ 75 ≈ $0.0867

Approximately:

8.7 cents per gram of protein

Method 2: Use protein per 100 grams

Sometimes nutrient information is listed per:

100 g

rather than by household serving.

This makes the calculation straightforward.

Formula:

Then:

Example

Package:

800 g

Price:

$8

Protein:

20 g per 100 g

Total protein:

800 ÷ 100 × 20

Cost per gram:

Protein costs:

5 cents per gram

Use USDA FoodData Central when a useful label is unavailable

Whole foods sometimes do not have a convenient Nutrition Facts panel available when you are planning.

USDA FoodData Central is an official food-composition database managed by USDA’s Agricultural Research Service and National Agricultural Library. It provides nutrient data that can be used to look up protein and other nutrients for foods.

When using database values, make sure you choose an entry that closely matches what you are actually purchasing.

For example, distinguish where relevant between:

raw

and:

cooked

or between different product formulations.

Do not take the protein value from one food and apply it to a materially different product simply because both have a similar name.

Use the actual product label when possible

For packaged foods, the label on the product you are buying is usually the most direct source.

This matters because two versions of the same general food can have different protein amounts.

For example, two yogurts may differ because of:

• Formulation
• Water content
• Added ingredients
• Serving size

So instead of assuming:

all yogurt = X grams protein

read the actual label.

FDA requires Nutrition Facts information to be presented in relation to the stated serving size, which is why the serving size and servings-per-container numbers should be checked before doing the calculation.

Do not use only protein per serving

Suppose:

Product A

$4 10 g protein per serving

Product B

$6 15 g protein per serving

At first, B looks better because it provides more protein per serving.

But suppose:

A contains:

8 servings

B contains:

4 servings

Total protein:

A:

B:

Cost per gram:

A:

B:

A provides protein at:

half the cost per gram

in this example.

Always calculate total package protein.

Do not compare package serving counts without checking serving size

One package may say:

10 servings

while another says:

7 servings

That does not automatically mean the first contains more food or protein.

Serving sizes can differ.

FDA says serving sizes are standardized within relevant categories to help consumers understand and compare nutrition information, but the amount still needs to be read alongside servings per container and nutrient values.

For protein economics, the safest shortcut is:

protein per serving × servings per container

rather than judging the serving count by itself.

Example: Greek yogurt comparison

Suppose:

Yogurt A

Price: $5.00 Servings: 5 Protein: 15 g per serving

Total protein:

Cost per gram:

$5 ÷ 75 ≈ $0.0667

About:

6.7 cents per gram

Yogurt B

Price: $6.00 Servings: 4 Protein: 20 g per serving

Total protein:

Cost per gram:

About:

7.5 cents per gram

Yogurt B contains more protein per serving.

Yogurt A provides protein at a lower cost per gram.

Those are two different advantages.

Example: eggs

Suppose a carton contains:

12 eggs

It costs:

$4.20

Assume the label for this hypothetical carton provides:

6 g protein per egg

Total protein:

Cost per gram:

$4.20 ÷ 72 ≈ $0.0583

Approximately:

5.8 cents per gram of protein

If another carton costs less per egg but the eggs have a different labeled protein amount, calculate the protein cost for each instead of assuming the cheaper egg is automatically the cheaper protein source.

Example: canned tuna

Suppose one multipack costs:

$8

It contains four cans.

Each can provides:

25 g protein in the amount you actually use

Total:

Cost per gram:

So:

8 cents per gram

If the cans contain liquid that you drain, make sure the nutrient information and the amount you are treating as edible food are interpreted consistently.

Edible yield can change protein economics

A grocery package’s total weight is not always fully edible.

Examples can include foods containing:

• Bones
• Shells
• Peels
• Significant trimming
• Drained liquid

USDA’s Food Buying Guide specifically distinguishes As Purchased, or AP, from Edible Portion, or EP, and provides yield information because the amount purchased may differ from the amount available for serving.

That distinction matters when calculating the real cost of protein.

Example with edible yield

Suppose meat costs:

$8 per kg

You buy:

1 kg

but your relevant edible yield is:

80%

Usable amount:

Suppose the usable food provides:

20 g protein per 100 g

Total protein:

Cost per gram protein:

or:

5 cents per gram

If you had incorrectly assumed the full 1 kg was edible:

Total theoretical protein:

Incorrect apparent protein cost:

That would make the product appear cheaper than it actually is on an edible basis.

The yield percentage here is only an example. Use food-specific data where yield materially matters.

Use this yield-adjusted formula

First:

Then:

Finally:

This is especially useful when comparing foods with significantly different edible yields.

Do not apply the same yield factor to every meat

Bone content and trimming can vary substantially.

USDA’s Food Buying Guide uses food-specific yield information rather than one universal edible-yield percentage.

So avoid rules such as:

all bone-in meat is 70% edible

unless you have reliable data for the exact product or a reasonable measured household yield.

A later article in this series covers bone-in versus boneless food by real cost in more detail.

Protein cost from a boneless package is usually simpler

If a package is essentially fully intended for consumption, you may be able to work directly from:

package weight

and:

protein per 100 g

Example:

Boneless product:

750 g

Price:

$7.50

Protein:

22 g per 100 g

Total protein:

Cost:

$7.50 ÷ 165 ≈ $0.0455 per gram protein

About:

4.5 cents per gram

Again, the nutrient value is hypothetical. Use the actual product label or suitable food-composition data.

Raw versus cooked data can create misleading comparisons

Be careful when one protein value refers to:

raw food

and another refers to:

cooked food

For grocery-price analysis, compare quantities on a consistent basis.

If you purchased raw chicken but use a cooked nutrient entry, you may need a cooking-yield adjustment.

The simplest approach is often:

raw price + raw nutrition value

or:

cooked edible quantity + cooked nutrition value

rather than mixing the two.

USDA’s Food Buying Guide provides yield tools because preparation can change how much usable food comes from the amount purchased.

Cooking does not create free grocery value

Suppose a cooked food appears to have more protein per 100 g than its raw version.

That does not mean the cooking process magically created a cheaper protein source.

A change in water content can change nutrient concentration per 100 g.

For grocery economics, keep the purchase weight, cooked yield, and nutrition basis consistent.

Otherwise you can produce a mathematically neat but practically meaningless comparison.

A simple cooked-yield method

Suppose you buy:

1,000 g raw food for $10

After your normal preparation:

750 g cooked edible food remains

Your observed yield:

Suppose your chosen cooked nutrition information states:

30 g protein per 100 g cooked

Total cooked protein:

Cost per gram:

$10 ÷ 225 ≈ $0.0444

Approximately:

4.4 cents per gram protein

The numbers are examples.

The important point is that:

750 g cooked

must be paired with:

protein per 100 g cooked

rather than a raw nutrient value.

Cost per gram is different from cost per serving

Suppose a food costs:

5 cents per gram of protein

Your meal provides:

25 g protein from that food

Protein-food cost for that amount:

If another person’s portion provides:

40 g protein

Cost:

The protein source has the same cost per gram.

The meal costs differ because the quantities differ.

Use cost per gram for comparison

Cost per gram is particularly useful when comparing protein foods independent of your particular portion.

For example:

Food A:

4 cents per gram protein

Food B:

7 cents

Food C:

10 cents

A gives the lowest protein cost by this specific measure.

That does not automatically make A the best food overall.

It simply tells you:

A is cheapest per gram of protein.

Cost per gram protein is not a complete nutrition score

Protein foods also differ in:

• Calories
• Fat
• Carbohydrate
• Fiber
• Sodium
• Vitamins
• Minerals
• Ingredients
• Preparation requirements
• Convenience
• Taste

A food with the lowest protein cost is not automatically the most appropriate choice for every meal or person.

Use the calculation as:

one economic metric

not a ranking of overall food quality.

It also does not measure protein quality by itself

The formula treats:

1 gram protein

as one gram for cost calculation.

It does not evaluate amino acid profile, digestibility, or how foods fit the rest of the diet.

If your question is purely:

How many dollars am I paying per gram of listed protein?

the simple formula is useful.

Do not interpret it as answering every nutritional question about the food.

Calculate protein per dollar by reversing the formula

Sometimes:

grams of protein per dollar

is easier to understand.

Formula:

Example:

Package contains:

120 g protein

Price:

$6

Calculation:

Cost per gram:

These are inverse ways of expressing the same underlying value.

5 cents per gram protein

equals:

20 grams protein per dollar

assuming the same currency basis.

Use whichever number feels more intuitive

You may prefer:

$0.05 per gram protein

or:

20 g protein per $1

Both can be useful.

For grocery comparison, I often prefer:

cost per gram

because lower is better.

For quick value communication:

protein per dollar

can be easier because higher is better.

Example

Food A:

$4

80 g protein total

Cost per gram:

Protein per dollar:

Food B:

$4

50 g protein

Cost per gram:

Protein per dollar:

Both calculations tell the same story.

Food A gives more protein for the same money.

Calculate cost per gram using sale price when that is what you actually pay

Suppose normal price:

$6

Sale price:

$4.50

Total protein:

90 g

Regular protein cost:

$6 ÷ 90 ≈ $0.0667

Sale protein cost:

At the sale price:

5 cents per gram

But the discount is only relevant when you actually need and use the food.

A sale does not make wasted food economical.

Bulk packages can have a lower protein cost

Suppose:

Small package

$5 100 g protein total

Cost:

5 cents per gram

Bulk package

$12 300 g protein total

Cost:

Bulk:

4 cents per gram

Potential saving:

1 cent per gram protein

Across 300 g protein:

Buying equivalent small packages would cost:

Bulk package:

$12

Potential full-use saving:

$3

But only if the bulk quantity is actually used.

Waste can make cheap protein expensive

Suppose a bulk food costs:

$10

and theoretically contains:

200 g protein

Expected cost:

But 25% of the edible food is discarded and the discarded portion contains roughly the same protein concentration.

Protein actually consumed:

150 g

Effective cost:

$10 ÷ 150 ≈ $0.0667

Now the protein you actually ate cost:

6.7 cents per gram

instead of the expected 5 cents.

EPA recommends planning purchases around actual household needs and buying quantities that will realistically be used to reduce wasted food and unnecessary spending.

Carry-forward food is not waste

Suppose you buy a dry food containing:

200 g total protein

This week you consume only:

50 g of that protein

The rest of the package remains appropriately stored in your pantry.

Do not calculate:

and claim that is your cost per gram.

You still own food containing the remaining protein.

The package-level calculation remains useful as long as you reasonably expect to consume the rest.

This is different from food that is actually discarded.

Use actual consumed protein only for waste-adjusted analysis

There are therefore two useful calculations.

Purchase protein cost

Waste-adjusted protein cost

The first evaluates the deal when you buy it.

The second evaluates what happened afterward.

For stable foods that remain usable, the first usually makes more sense.

For repeatedly wasted perishables, the second can reveal the true cost of overbuying.

Do not forget drained weight

Suppose a canned food says:

400 g net weight

but much of that weight is liquid you normally discard.

Using:

400 g × protein per 100 g of drained food

may produce the wrong result if the nutrient basis and weight basis do not match.

Look for:

• Drained weight
• Serving information
• Product-specific nutrient data

and keep the quantities consistent.

The same principle applies to any food where the amount purchased is materially different from the amount you eat.

Price per can can hide protein differences

Suppose:

Can A

$1.50 18 g total protein

Can B

$1.80 30 g total protein

A is cheaper per can.

Protein cost:

A:

$1.50 ÷ 18 ≈ $0.0833

B:

B costs more at checkout but provides cheaper protein.

This is exactly the kind of comparison price-per-package cannot reveal.

Cost per 100 grams of food can also hide protein differences

Suppose:

Food A

$0.80 per 100 g 8 g protein per 100 g

Protein cost:

Food B

$1.20 per 100 g 24 g protein per 100 g

Protein cost:

B costs:

50% more per 100 g of food

but protein costs:

50% less per gram

Again, grocery price and protein value are different measures.

Build a protein-value table

A practical comparison can look like this:

By protein cost alone:

Food B provides the best value.

But you can then evaluate other factors separately.

Do not mix currencies

If comparing prices from different stores or countries, convert all prices into the same currency before calculating.

For example:

Product A:

PKR

Product B:

USD

You cannot directly compare:

0.05 PKR per gram

with:

$0.05 per gram

without currency conversion.

The same applies when comparing historical prices from different periods if inflation-adjusted analysis is the goal.

For an ordinary grocery trip, use today’s actual prices in the same currency.

Do not mix package sale units

Suppose one chicken package is priced:

per kilogram

and another has:

one total package price

Calculate the actual package cost first.

Example:

Product A:

750 g

$8/kg

Package price:

Then calculate protein value from that $6.

This keeps the price basis consistent.

Use price actually paid after relevant discounts

If your receipt shows:

Original:

$8

Coupon:

-$2

Actual:

$6

Use:

$6

when calculating your personal purchase cost.

If you are building a general price comparison for readers, use the ordinary available price rather than a one-person coupon unless you label it clearly.

Do not include an entire recipe cost when calculating one ingredient’s protein value

Suppose chicken costs:

$6

but the full chicken-rice meal costs:

$10

If you are calculating:

cost per gram of protein from the chicken

use the chicken cost and chicken protein.

If you are calculating:

total meal cost per gram of protein

then use:

Those are different metrics.

Calculate protein cost for a complete recipe

The same formula works for an entire meal.

Suppose a recipe costs:

$12

and contains:

120 g protein total

Recipe protein cost:

If the recipe makes:

4 portions

Total protein per portion:

Cost per portion:

Both calculations are consistent:

But recipe protein can come from several ingredients

A bean and rice bowl might receive protein from:

• Beans
• Rice
• Yogurt
• Cheese
• Other ingredients

If you are calculating meal protein economics, include the protein and cost of the entire meal.

If you are comparing beans as a protein source, isolate the beans.

Define your question before doing the arithmetic.

Cost per gram protein can help compare substitutions

Suppose a meal can use either:

Food A:

$2.50 50 g total protein

5 cents per gram

Food B:

$3 75 g total protein

4 cents per gram

B is cheaper on a protein basis.

But perhaps A:

• Fits the recipe better
• Has a different calorie profile
• Requires less preparation
• Is preferred by the household

Protein cost is a decision aid, not an automatic substitution rule.

Convenience changes total meal economics

Suppose one protein requires:

• Soaking
• Long cooking
• Additional ingredients

and another is ready to eat.

Cost per gram protein may favor the first.

But whether that savings is worthwhile depends on your meal-planning priorities.

Do not force every grocery decision into a single metric.

This article is about identifying protein cost accurately, not declaring that cost is the only thing that matters.

A one-person grocery example

Suppose you are comparing two foods for several lunches.

Food A

Price:

$5

Protein per serving:

20 g

Servings:

4

Total protein:

80 g

Cost per gram:

Food B

Price:

$6

Protein per serving:

30 g

Servings:

4

Total:

120 g

Cost per gram:

Food B costs:

$1 more

but provides protein for:

1.25 cents less per gram

If you will use the full package and both foods fit your meal plan, B offers better protein value.

A family package example

Suppose your family is comparing:

Small chicken package

Price:

$7

Total calculated protein:

140 g

Protein cost:

Family package

Price:

$18

Total protein:

450 g

Protein cost:

Family package saves:

1 cent per gram protein

Potential saving over 450 g protein:

Equivalent small-package protein cost:

Bulk cost:

$18

Potential saving:

$4.50

But only if the larger amount fits the household’s meals and storage plan.

A reusable protein-cost worksheet

Food:

—

Price paid:

—

Protein per serving:

g

Servings per package:

—

Protein per serving × servings per package

Total protein:

g

Price ÷ total protein

Cost per gram protein:

—

Total protein ÷ price

Protein per currency unit:

g

Is the whole package edible?

Yes / No

Does the product contain significant:

Bone / shell / trimming / drained material?

If yes, adjust the usable quantity or use suitable edible-portion data.

Will the food realistically be used?

Yes / No

If a significant amount is regularly discarded, calculate the waste-adjusted result separately.

The fastest packaged-food shortcut

If the label says:

Protein = P grams per serving

Servings per container = S

and package price is:

C

then:

Example:

Price:

$4.50

Protein:

15 g

Servings:

6

Calculation:

$4.50 ÷ (15 × 6)

$4.50 ÷ 90

= $0.05 per gram protein

That is the simplest version of the calculation.

The fastest per-100-gram shortcut

If:

Food price = C

Package weight = W

Protein per 100 g = P

Then:

and:

Example:

Price:

$6

Weight:

600 g

Protein:

20 g per 100 g

Total protein:

Cost:

Common mistakes

Comparing package prices instead of protein totals

A more expensive package can still provide cheaper protein.

Comparing price per kilogram of food alone

Different foods contain different protein amounts.

Comparing protein per serving while ignoring servings per package

Calculate total package protein.

Assuming the label serving is how much you personally should eat

FDA says label serving sizes describe amounts people typically consume and are not individualized intake recommendations.

Comparing raw nutrition data with cooked food weight

Keep the food state consistent.

Ignoring bones, shells, or significant trimming

USDA distinguishes As Purchased and Edible Portion amounts because purchase quantity does not always equal usable food quantity.

Applying one edible-yield percentage to every food

Use food-specific information when yield materially affects the calculation.

Treating pantry carry-forward as wasted food

Unused but appropriately stored future inventory still contains value.

Ignoring food actually discarded

Repeated waste increases the effective cost of protein consumed.

Assuming the cheapest protein is automatically the best food

Protein cost does not evaluate the entire nutritional profile or suitability of the food.

Comparing different currencies without conversion

Use one currency.

Using a database entry that does not match the actual product

Use the product label where available or select an appropriately matching USDA FoodData Central entry.

Calculate the protein first, then divide the price

The simplest way to compare protein value is to stop asking:

Which protein food has the cheapest package?

Instead ask:

How much total protein does that package contain?

For a packaged food:

Then:

If nutrition information is stated per 100 grams:

Then divide the price by that amount.

Use the actual product’s Nutrition Facts label when possible. FDA explains that nutrition values are linked to the serving information shown on the label, while USDA FoodData Central can provide food-composition information when a suitable label is unavailable.

For foods containing significant bone, shell, trimming, or other non-edible material, consider edible yield before deciding how much protein the purchase really provides. USDA’s Food Buying Guide specifically distinguishes food as purchased from its edible portion for purchasing and cost calculations.

Finally, remember what the result means.

If chicken works out to:

4 cents per gram of protein

and yogurt works out to:

7 cents

that tells you chicken is cheaper by this particular protein-cost measure.

It does not automatically mean you should replace yogurt with chicken or choose every meal according to the lowest number.

Use protein cost to answer one focused grocery question:

How much am I paying for the protein this food provides?

Once you know that number, comparing prices becomes much more meaningful than looking at package cost alone.