Protein Calculator
Find how many grams of protein to eat each day for your weight, age and what you do, from staying healthy to building muscle.
What 78 g looks like
| Food | Typical protein | For your day |
|---|
Typical values, rounded; brands and recipes vary, so check the label. "For your day" is how many servings would cover your whole target on their own.
How your protein is worked out
Your weight, times the grams per kg that fit what you do, shared over your meals.
- 1
Your weight
body weight
= 65 kg - 2
Grams per kg
65 × 1.2 g
= 78 g a day - 3
Your range
65 × 1.1 to 1.4
= 72–91 g - 4
Each meal
78 ÷ 3 meals
= 26 g each
Read more: the formula, a worked example and the guide ranges
Protein needs grow with your body size and with how much you train. This calculator multiplies a weight (your body weight, or in Advanced your lean mass, adjusted weight or goal weight) by the grams per kg that fit what you do. It raises the range for adults aged 65 and over, adds extra for the second half of pregnancy and breastfeeding, and then shares the total over your meals. It also shows the protein as a share of your daily calories and what that amount looks like in everyday foods.
The formula
Protein a day = weight in kg × grams per kg for what you do (+ 25 g if pregnant in the 2nd or 3rd trimester or breastfeeding)
Range = weight × low g per kg to weight × high g per kg
Per meal = protein a day ÷ meals
Share of calories = protein × 4 kcal ÷ daily calories
With lean mass, the grams per kg are 1.25 times the body-weight figures (a typical adult is about 20% fat). Lean mass = weight × (1 − body fat %), or, with no body fat entered, the Boer estimate: men 0.407 × kg + 0.267 × cm − 19.2; women 0.252 × kg + 0.473 × cm − 48.3. Adjusted body weight = ideal weight (Devine) + 0.4 × (weight − ideal weight). When daily calories are left blank, they are estimated as Mifflin–St Jeor resting burn × an activity factor for what you picked (20% less when losing fat).
Worked example
A 30-year-old woman, 165 cm and 65 kg, who exercises 3–5 days a week. Her BMI is 65 ÷ 1.65² = 23.9, under 30, so the calculator uses her body weight. Regular exercise is 1.1–1.4 g per kg with a 1.2 g target: 65 × 1.2 = 78 g a day, with a range of 65 × 1.1 = 71.5, about 72 g, to 65 × 1.4 = 91 g. 65 kg is 143.3 lb, so that's 78 ÷ 143.3 = 0.54 g per lb. The RDA minimum would be 0.8 × 65 = 52 g.
Over 3 meals that's 78 ÷ 3 = 26 g each. Her estimated calories are (10 × 65 + 6.25 × 165 − 5 × 30 − 161) × 1.55 = 1,370.25 × 1.55 = 2,123.9, about 2,120 kcal. Protein gives 78 × 4 = 312 kcal, which is 312 ÷ 2,120 = 14.7% of her calories, inside the usual 10–35%. As food, 78 g is about 13 large eggs (78 ÷ 6) or about 250 g of cooked chicken breast (78 ÷ 31 × 100).
If she entered 30% body fat and picked lean mass: 65 × 0.70 = 45.5 kg lean, × 1.5 g per kg of lean mass (1.2 × 1.25) = 68.25, about 68 g.
Guide ranges used
| What you do | g per kg a day | Target |
|---|---|---|
| General health, little exercise | 0.8–1 | 0.8 |
| Light exercise, 1–3 days a week | 1–1.2 | 1.1 |
| Regular exercise, 3–5 days a week | 1.1–1.4 | 1.2 |
| Endurance training (running, cycling) | 1.2–1.6 | 1.4 |
| Strength training, building muscle | 1.6–2.2 | 1.8 |
| Losing fat, keeping muscle | 1.6–2.4 | 2 |
The 0.8 g per kg RDA for adults and the extra 25 g a day in the second half of pregnancy and while breastfeeding come from the US and Canadian Dietary Reference Intakes (National Academies); they are guidelines, not exact needs. For ages 65 and over the range is raised to at least 1–1.2 g per kg (target 1.1), as suggested by the PROT-AGE study group. The exercise ranges follow sports nutrition guidance such as the ISSN position stand and a 2018 review that found muscle gains level off near 1.6 g per kg. The share of calories is compared with the usual adult range of 10–35%. About 0.4 g per kg in a meal is a common target for building muscle. Lean-mass figures are 1.25 times the body-weight figures.
Food equivalents (typical)
| Food | Serving | Protein |
|---|---|---|
| Chicken breast, cooked | 100 g | 31 g |
| Tuna, canned in water | 100 g | 25 g |
| Salmon, cooked | 100 g | 22 g |
| Egg, large | 1 egg (50 g) | 6 g |
| Greek yogurt, plain | 170 g pot | 17 g |
| Paneer | 100 g | 18 g |
| Milk | 250 ml glass | 8 g |
| Whey protein powder | 1 scoop (30 g) | 24 g |
| Tofu, firm | 100 g | 14 g |
| Lentils (dal), cooked | 1 cup (200 g) | 18 g |
| Chickpeas, cooked | 1 cup (165 g) | 15 g |
| Soya chunks, dry | 50 g | 26 g |
| Peanuts | 30 g handful | 8 g |
| Quinoa, cooked | 1 cup (185 g) | 8 g |
Typical values rounded from USDA FoodData Central; real foods and brands vary. Plant proteins are a little less digestible than animal ones, so vegans may want to aim for the upper part of their range and mix sources such as beans, lentils, soya and grains through the day.
These are estimates for healthy adults. They're not suitable for under-18s. Ask a doctor or registered dietitian before eating a lot more protein if you have kidney disease or another medical condition, and for your own needs in pregnancy.
Common questions
How much protein do I need a day?
The usual adult guideline (the RDA) is 0.8 g of protein per kg of body weight a day, about 52 g for someone who weighs 65 kg. That's a minimum for inactive adults. People who exercise often aim higher: about 1.1–1.4 g per kg for regular exercise and 1.2–1.6 g per kg for endurance training.
How much protein do I need to build muscle?
For strength training, the calculator uses 1.6–2.2 g per kg of body weight a day, with 1.8 g per kg as the target. Research suggests muscle gains level off near 1.6 g per kg, with 2.2 g per kg as an upper figure. Spreading it over 3–5 meals of about 0.4 g per kg each is a common approach.
How much protein should I eat when losing weight?
Eating more protein while you cut calories helps you keep muscle. The calculator uses 1.6–2.4 g per kg of body weight a day, with 2.0 g per kg as the target. If you carry a lot of body fat, base it on lean mass, adjusted weight or your goal weight instead of your full weight.
Do older adults need more protein?
Yes. Expert groups suggest healthy adults over 65 eat at least 1.0–1.2 g of protein per kg a day, more than the 0.8 g per kg RDA, to help keep muscle and strength. The calculator raises the range to at least 1.0–1.2 g per kg automatically when you enter an age of 65 or more.
How much extra protein do I need when pregnant or breastfeeding?
The US and Canadian guidelines add about 25 g of protein a day in the second and third trimesters and while breastfeeding, and nothing extra in the first trimester. The calculator adds the 25 g on top of your range. Check your own needs with your doctor or midwife.
Should I use my full weight if I'm overweight?
Not always. Using your full weight can give a very high number if you carry a lot of body fat. With a BMI of 30 or more, the calculator switches to adjusted body weight: ideal weight plus 40% of the extra. In Advanced you can use lean mass, adjusted weight or a goal weight instead.
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