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Protein calculator
Most adults who want to lose fat, keep muscle or build it do best on about 1.6–2.2 g of protein per kg of a healthy body weight a day (0.73–1.00 g per lb): double or more the 0.8 g/kg RDA, which is only the minimum to avoid deficiency. For a woman of 75 kg (165 lb) and 165 cm losing weight that's about 125 g a day, or 30 g at each of 4 meals. The calculator works it out for your goal and shows what it looks like in food.
What makes this protein calculator different
- It doesn't give you protein for your fat. Most calculators multiply your total weight, so a man of 115 kg (254 lb) gets told 230 g a day. Muscle needs protein; fat doesn't. This one uses your goal weight or the weight at a BMI of 25, or your lean mass if you know your body fat, which gives him 145 g.
- It shows a range, the minimum and the per-meal split, not one number.
- It turns grams into food, with USDA values and plant-based options.
- It agrees with the rest of Deficitly: the macro calculator and the app use the same rules.
Protein a day by goal
| Person | Lose fat | Maintain | Build muscle |
|---|---|---|---|
| Woman, 60 kg 132 lb163 cm | 110 g | 95 g | 110 g |
| Woman, 75 kg 165 lb165 cm | 125 g | 110 g | 125 g |
| Woman, 95 kg 209 lb165 cm | 125 g | 110 g | 125 g |
| Man, 75 kg 165 lb178 cm | 135 g | 120 g | 135 g |
| Man, 90 kg 198 lb180 cm | 145 g | 130 g | 145 g |
| Man, 115 kg 254 lb180 cm | 145 g | 130 g | 145 g |
Why more while dieting? In a calorie deficit your body is more willing to break down muscle, and protein (with strength training) is what protects it; it also keeps you fuller than carbs or fat. See how much protein to lose weight and how much protein to build muscle.
The RDA is a minimum, not a target
The official RDA of 0.8 g per kg of body weight is the amount that prevents deficiency in almost everyone, about 46 g a day for a reference woman and 56 g for a man. It isn't designed for people who diet, train or are over 65. For them, 1.2–2.2 g/kg is where the research points. More in how much protein do I need a day?
Protein for women
The rules are the same per kg; women simply have lower reference weights, so the grams are lower. While dieting, keep fat at about 0.8 g per kg of a healthy weight too: carbs should give way first (macro calculator). In pregnancy and breastfeeding needs go up; follow your midwife or doctor (calories while breastfeeding).
Protein over 65
Muscles respond less to protein with age, so older adults need more, not less: at least 1.0–1.2 g per kg of body weight a day (PROT-AGE), more if active or recovering from illness, and about 25–30 g at each meal. Strength training doubles the benefit.
How much protein per meal?
Spread it out: about 0.4 g per kg at each of 4 meals (roughly 25–40 g) is a good pattern for muscle. The old "your body can only use 30 g at once" isn't right: bigger servings take longer to use, not wasted. See how much protein per meal.
Protein in food
| Food | Protein | Per 100 kcal |
|---|---|---|
| Chicken breast, roasted100 g (3.5 oz) | 31.0 g | 18.8 g |
| Tuna, light, canned in water1 can, drained (165 g) | 32.1 g | 22.6 g |
| Shrimp, cooked3 oz (85 g) | 20.4 g | 24.2 g |
| Ground beef 90% lean, cooked3 oz (85 g) | 22.2 g | 12.0 g |
| Salmon, farmed, cooked3 oz (85 g) | 18.8 g | 10.7 g |
| Egg, large1 egg (50 g) | 6.3 g | 8.8 g |
| Greek yogurt, plain, nonfat1 pot (170 g) | 17.3 g | 17.3 g |
| Cottage cheese, 2%½ cup (113 g) | 11.8 g | 12.9 g |
| Milk, 1%1 cup (244 g) | 8.2 g | 8.0 g |
| Tofu, firm½ cup (126 g) | 11.4 g | 11.6 g |
| Edamame, cooked1 cup (155 g) | 18.5 g | 9.8 g |
| Lentils, cooked1 cup (198 g) | 17.9 g | 7.8 g |
| Chickpeas, cooked1 cup (164 g) | 14.5 g | 5.4 g |
| Oats, dry½ cup (40 g) | 5.3 g | 3.5 g |
| Peanut butter2 tbsp (32 g) | 7.1 g | 3.7 g |
| Almonds1 oz (28 g) | 6.0 g | 3.7 g |
Lean meat, fish, egg whites, Greek yogurt and cottage cheese give the most protein per calorie, which helps most when you're eating less. Beans, lentils and nuts bring fibre but more calories per gram of protein. Plant eaters reach the same targets with tofu, edamame, lentils, beans and a protein powder if needed, mixing sources over the day. Full lists: high-protein foods and high-protein, low-calorie foods.
Can you eat too much protein?
For healthy people, intakes well above these targets haven't been shown to harm the kidneys, and no official upper limit exists. People with kidney disease are the exception and need their doctor's guidance. More in how much protein is too much?
Sources
- Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press, 2005 (RDA 0.8 g/kg; AMDR 10–35% of energy; no upper limit set).
- 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.
- Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med 2018;52(6):376–384.
- Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. J Int Soc Sports Nutr 2018;15:10.
- Bauer J, Biolo G, Cederholm T, et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc 2013;14(8):542–559.
- U.S. Department of Agriculture, Agricultural Research Service. FoodData Central, SR Legacy (2018). Food IDs in the table notes.