Protein Calculator: Daily Protein Intake & RDA

Simple protein calculator

A protein calculator is a tool that adds up the protein in a list of foods and compares the total to a recommended daily amount. This one lets a person pick foods from a database, enter how much of each they ate in grams, and see the running total along with a percentage of their own recommended daily protein intake.

What protein does

Protein is a nutrient made of amino acids. The body uses it to build and repair muscle, skin, and other tissue, to make enzymes and hormones, and to support the immune system. Unlike fat, the body cannot store much extra protein for later, so a regular supply through food matters.

How to calculate daily protein needs

Recommended daily protein intake formula

The standard reference amount, set by the U.S. National Academies of Sciences, Engineering, and Medicine, is:

Recommended daily protein (g) = 0.8 × body weight (kg)

This is the Recommended Dietary Allowance (RDA), the amount that prevents deficiency in most healthy adults. It is not a target for building muscle or for athletes, who typically need more. Common ranges used by nutrition researchers:

Because the formula is per kilogram of body weight, it gives a different answer for every person. A fixed number of grams, without a body weight attached, does not mean much on its own.

If weight is measured in pounds, convert it to kilograms first by multiplying by 0.4536 (1 lb = 0.45359237 kg).

How the calculator works

1. Select a food from the list. Foods are grouped by category, such as meat, fish, dairy, legumes, nuts, grains, and plant-based proteins.
2. Enter the amount eaten, in grams.
3. Select "Add Food." The food and its protein content are added to the list, and the running total updates.
4. Repeat for each food eaten.
5. Optionally, enter body weight and choose kg or lb. The calculator then shows the total protein as a percentage of the recommended daily intake for that weight.

Each food in the database lists protein per 100 grams, along with how it was measured: cooked, dry, or as eaten. This matters because raw and cooked weights differ. For example, dry oats have about 13.2 g of protein per 100 g, while cooked oatmeal has much less per 100 g because it has absorbed water. Meat and fish figures in this calculator are for the cooked weight.

Formula for each food

Protein from one food (g) = (protein per 100 g × grams eaten) ÷ 100

The calculator adds this figure for every food entered to get the total protein for the day.

Formula for the percentage shown

Percentage of recommended intake = (total protein ÷ recommended daily protein) × 100

The recommended daily protein used here is calculated from the body weight entered into the calculator, not a fixed figure. Two people with the same total protein intake will see different percentages if they enter different body weights, because each has a different recommended amount.

Worked example

Suppose someone eats the following in a day:

• 100 g of cooked chicken breast (31 g protein per 100 g)
• 200 g of Greek yogurt (10 g protein per 100 g)
• 150 g of cooked salmon (25 g protein per 100 g)

Protein from each food:

• Chicken breast: (31 × 100) ÷ 100 = 31 g
• Greek yogurt: (10 × 200) ÷ 100 = 20 g
• Salmon: (25 × 150) ÷ 100 = 37.5 g

Total protein: 31 + 20 + 37.5 = 88.5 g

If this person weighs 70 kg, their recommended daily protein is 0.8 × 70 = 56 g. The percentage shown is (88.5 ÷ 56) × 100 ≈ 158% of the recommended amount. For a lighter person, say 55 kg, the recommended amount is 0.8 × 55 = 44 g, and the same 88.5 g of food would show as (88.5 ÷ 44) × 100 ≈ 201%. The percentage always depends on the body weight entered, not on a single fixed baseline.

Protein content of common foods

Values are grams of protein per 100 grams of the food, based on U.S. Department of Agriculture (USDA) data.

Meat, fish, legumes, and cooked grains are listed by their cooked weight, since that is how most people measure a serving. Oats are listed dry, since that is how they are usually weighed before cooking. Nuts, seeds, dairy, eggs, and plant-based proteins like tofu and tempeh are listed as eaten.

Animal proteins such as meat, fish, eggs, and dairy contain all nine essential amino acids the body cannot make on its own, so they are described as "complete" proteins. Most plant proteins are lower in one or more essential amino acids, but eating a variety of plant foods across the day, such as legumes with grains, supplies the same amino acids overall.

Protein needs for different groups

Protein needs are not identical for everyone. Beyond the general 0.8 g/kg guideline:

• Older adults tend to need more, around 1.0–1.2 g/kg, because aging reduces how efficiently the body builds muscle from dietary protein.
• Athletes and very active people typically need 1.2–2.0 g/kg to support muscle repair after exercise.
• People following a weight-loss diet often benefit from higher protein intake to help preserve muscle while losing fat.

These ranges come from general nutrition research and are shown for context. The calculator itself always compares total protein intake to the standard 0.8 g/kg RDA for the body weight entered, since that is the figure with the widest scientific support.

Frequently asked questions

How much protein do I need per day? Multiply body weight in kilograms by 0.8 to get the RDA. A 70 kg adult needs about 56 g per day under this guideline. Athletes and older adults are often advised to eat more, up to about 2.0 g per kilogram.

How does the calculator work out the percentage shown? It divides the total protein from the foods entered by the recommended daily intake for the body weight and unit entered, then multiplies by 100. Without a body weight entered, no percentage is shown, since the recommended amount cannot be calculated.

Why does the same food total show different percentages for different people? Because the recommended daily amount is per kilogram of body weight. A heavier person has a higher recommended amount in grams, so the same total protein intake is a smaller percentage of their target than it would be for a lighter person.

Are the food values raw or cooked? It depends on the food. Meat, fish, and most cooked legumes and grains are listed by cooked weight. Oats are listed dry. Dairy, eggs, nuts, and foods like tofu and tempeh are listed as eaten. The calculator labels each food with its basis.

Is more protein always better? No. The 0.8 g/kg figure is a minimum to prevent deficiency, not a ceiling. Higher intakes, up to roughly 2 g/kg, are considered safe for most healthy adults, but there is no established benefit to consuming far more than the body can use for repair and maintenance.

Can plant-based eaters get enough protein? Yes. Eating a range of plant proteins across the day, such as legumes, whole grains, nuts, and soy foods like tofu and tempeh, can supply all essential amino acids, though slightly higher total intake is sometimes recommended to offset lower digestibility in some plant foods.

References

1. National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids.
2. Paddon-Jones D, Rasmussen BB. "Dietary protein recommendations and the prevention of sarcopenia." Curr Opin Clin Nutr Metab Care. 2009;12(1):86-90.
3. Jäger R, Kerksick CM, Campbell BI, et al. "International Society of Sports Nutrition Position Stand: protein and exercise." J Int Soc Sports Nutr. 2017;14:20.
4. U.S. Department of Agriculture, FoodData Central.