Protein calculator

How the protein calculator works

Protein needs scale with body size, so research and nutrition guidelines usually express them in grams of protein per kilogram of body weight per day (g/kg). This calculator converts your weight to kilograms, picks a range based on your goal and activity, and multiplies.

The formula in plain words: daily protein in grams = your weight in kg x the low and high ends of your g/kg range. To convert pounds to kilograms, divide by 2.2046.

The ranges it uses:

• Maintain, mostly sitting: 0.8 to 1.0 g/kg. The lower end, 0.8 g/kg, is the Recommended Dietary Allowance for healthy adults, which is set to cover the needs of nearly all healthy adults.
• Maintain, with exercise: 1.0 to 1.2 g/kg with some exercise, and 1.2 to 1.6 g/kg with regular training. Sports nutrition position statements suggest about 1.2 to 2.0 g/kg for active people.
• Lose fat: 1.2 to 1.6 g/kg if you mostly sit, rising to 1.6 to 2.2 g/kg with regular training. Eating more protein during a calorie deficit helps you hold on to muscle and tends to keep you fuller.
• Build muscle: 1.6 to 2.2 g/kg. A large review of strength training studies found that extra muscle gains leveled off at around 1.6 g/kg on average, with 2.2 g/kg covering people who respond best.

The per meal numbers simply divide your daily range by 3 or 4. Spreading protein across meals, rather than eating most of it at dinner, is a sensible way to reach a higher target.

How to read your result

The large number is your daily range in grams. Anywhere inside it is a reasonable target, so there is no need to hit an exact number. If you find it hard to eat that much, aim for the low end. If you are training hard or eating in a calorie deficit, the upper half is a good place to be.

The tiles show the g/kg range used, the same range per pound, and how much protein to put on your plate at each meal. The table gives one example day of common foods that adds up to a total inside your range. It is there to make the number feel real, not as a meal plan. Swap in foods you like.

This is an estimate. If you carry a lot of extra body fat, your weight overstates your muscle, and many dietitians base protein on a goal or adjusted weight instead. Entering your goal weight is a simple way to do that.

A worked example

The calculator opens with a 170 lb person who trains 4 or more days a week and wants to build muscle.

1. Convert to kilograms: 170 divided by 2.2046 is about 77.1 kg.
2. Apply the build muscle range: 77.1 x 1.6 is about 123 g, and 77.1 x 2.2 is about 170 g. So the daily target is 123 to 170 g of protein.
3. Per meal: across 3 meals that is about 41 to 57 g each. Across 4 meals it is about 31 to 43 g each.

The example day for this result is 2 eggs (12 g), a cup of Greek yogurt (23 g), 4 oz of chicken breast (35 g), a cup of lentils (18 g), 4 oz of salmon (25 g), a cup of cottage cheese (28 g) and a cup of black beans (15 g), for about 156 g. That lands comfortably inside the range.

Mistakes to avoid

• Confusing grams of food with grams of protein. A 4 oz chicken breast weighs about 113 g but holds about 35 g of protein. Use the protein line on the label.
• Loading it all into one meal. Getting most of your protein at dinner makes a high target hard to reach. Include a solid source at every meal.
• Forgetting plant protein counts. Beans, lentils, tofu, dairy and grains all add up. A mix of sources also brings fiber and other nutrients.
• Pushing protein far past the range. Going well beyond the top of your range rarely adds benefit, and it can crowd out other foods you need.
• Expecting protein alone to build muscle. Muscle grows when you train it. Protein supports the work, it does not replace it.

Common questions

How much protein do I need a day?

For a healthy adult who is not very active, the baseline is 0.8 g per kg of body weight, about 0.36 g per pound. Active people, people losing fat and people building muscle usually do better with more, generally in the range of 1.2 to 2.2 g/kg depending on the goal.

Can I eat too much protein?

For healthy adults, intakes in the ranges shown here are generally considered safe. People with kidney disease or reduced kidney function may need to limit protein, so if that applies to you, talk to your doctor before eating more.

Do I need protein powder?

No. Powder is just a convenient food. If you can reach your range with regular meals, you do not need it. If you struggle to, a shake can help fill the gap.

Should I use my current weight or my goal weight?

If you are close to a healthy weight, use your current weight. If you have a lot of weight to lose, using your goal weight gives a more realistic number. A registered dietitian can help you set a target if you are unsure, are pregnant, or have a health condition.