How much protein do you need per day?
It depends mostly on two things: how much you move and whether you're eating less than you burn. In a calorie deficit your body is more willing to break down muscle, so protein needs go up. Lifting weights pushes them up further, because muscle you train needs material to repair.
| g per kg a day | Lose fat | Maintain | Build muscle |
|---|---|---|---|
| Mostly sitting | 1.2 to 1.6 | 0.8 to 1 | 1 to 1.2 |
| Active | 1.6 to 2 | 1.2 to 1.6 | 1.4 to 1.8 |
| Lifting weights | 1.8 to 2.4 | 1.6 to 2 | 1.6 to 2.2 |
To convert to grams per lb, divide by 2.2. So 1.8 g/kg is about 0.8 g/lb.
How to calculate your protein intake
Take your weight in kg and multiply it by the factor from the table. The calculator uses the middle of the range as your target. Someone who weighs 75 kg, goes running a few times a week and wants to lose fat lands at 1.6 to 2.0 g per kg, which is 120 to 150 g a day, so a target of 135 g.
Two adjustments. At a BMI of 30 or more, the calculator uses your weight at a BMI of 25, because fat tissue needs very little protein. And from 65 on it never goes below 1.0 to 1.2 g per kg, which is what the PROT-AGE group recommends for healthy older adults to keep muscle.
What your protein looks like on a plate
Numbers are easier to hit when you can picture them. Approximate values per typical portion:
- Chicken breast, cooked (150 g)46 g
- Firm tofu (150 g)26 g
- Greek yogurt, plain nonfat (200 g)20 g
- Cottage cheese (200 g)22 g
- Lentils, cooked (200 g)18 g
- Eggs (2 large)13 g
Building every meal around one of these gets most people to their target without a food scale. If you'd rather not add it up yourself, myCalCoach on Telegram estimates protein from a photo of your plate and tells you what's left for the day.
Protein and the rest of your diet
Protein is one part of the picture. For carbs and fat too, use the macro calculator. To see how many calories you need to lose weight, try the calorie deficit calculator.
Common questions
How much protein should I eat a day?
The official minimum for adults is 0.8 g per kg of body weight (0.36 g per lb). That prevents deficiency but is low for anyone who trains or is losing weight. Most active people do well on 1.6 to 2.2 g per kg (0.7 to 1 g per lb).
How do I calculate my protein intake?
Multiply your body weight in kg by a factor that fits your activity and goal, for example 1.8 if you lift weights and want to lose fat. A 75 kg person gets 135 g a day. If your BMI is 30 or higher, use the weight you would have at a BMI of 25 instead of your current weight.
Can I eat too much protein?
For healthy adults, intakes up to about 2.5 g per kg have not shown harm in studies. If you have kidney disease, ask your doctor first, because your limit may be much lower.
Does protein timing matter?
Less than the daily total. Spreading protein over three or four meals of roughly 0.4 g per kg each seems to work slightly better for muscle than one or two big servings.
Should I base protein on my goal weight?
If you have a lot of weight to lose, yes. Protein needs track lean mass, not fat mass, so total weight overestimates them. This calculator switches to your weight at a BMI of 25 once your BMI reaches 30.
Other free calculators
Sources
- Jäger R, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20.
- Morton RW, 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. Br J Sports Med. 2018;52(6):376-384.
- Helms ER, et al. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes. Int J Sport Nutr Exerc Metab. 2014;24(2):127-138.
- Bauer J, 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.
- Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? J Int Soc Sports Nutr. 2018;15:10.
- Food values: USDA FoodData Central, rounded.
This calculator gives general estimates and is not medical advice. If you have kidney disease, are pregnant or under 18, talk to a doctor before changing how much protein you eat.