FitDiaryProtein intake calculator: how much protein per day
See how many grams of protein to eat a day for your weight and goal, and how to spread them over your meals. It’s free and works in kg or lb.
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Enter your weight to see how much protein you need.
How much protein do you need a day?
Adults need about 0.8 g of protein per kg of body weight a day (the US recommended dietary allowance). If you exercise, aim higher: about 1.6 to 2.2 g per kg, based on a 2018 analysis of 49 strength-training studies. For a 70 kg adult, that’s 56 g at the basic level and 112 to 154 g with regular training.
The calculator gives one number for your goal, the same one the FitDiary app uses, and shows the research range around it.
How the protein calculator works
It multiplies your weight by a factor for your goal. These are the factors the FitDiary app uses:
| Goal | Per kg of body weight | Per lb |
|---|---|---|
| Build muscle | 2.2 g | 1.0 g |
| Lose weight | 2.0 g | 0.9 g |
| Maintain or gain weight | 1.8 g | 0.8 g |
The International Society of Sports Nutrition position stand (2017) says 1.4 to 2.0 g per kg a day is enough for most people who exercise to build and keep muscle.
A 2018 meta-analysis of 49 studies on strength training found that gains in lean mass levelled off at about 1.6 g per kg a day, with 2.2 g per kg as the upper end of the estimate. That’s where the 1.6 to 2.2 g range in the calculator comes from.
The 0.8 g per kg is the recommended dietary allowance (RDA) for adults set by the US National Academies. It covers basic needs, not the extra needs of training.
Want your calories and the other macros too? The macro calculator uses the same protein factors, and the TDEE calculator works out how many calories you burn.
Worked example
Take someone who weighs 70 kg (154 lb) and wants to lose weight:
- Protein = 70 kg × 2.0 g = 140 g a day (0.9 g per lb), which is 560 kcal.
- Research range: 70 × 1.6 = 112 g to 70 × 2.2 = 154 g a day.
- Over three meals that’s about 47 g each; over four meals, 35 g each.
- For comparison, the adult RDA of 0.8 g per kg would be 56 g.
Protein per day by body weight
Daily protein in grams, using the app’s factors and the research range:
| Body weight | Maintain (1.8 g/kg) | Lose weight (2.0 g/kg) | Build muscle (2.2 g/kg) | Range (1.6–2.2 g/kg) |
|---|---|---|---|---|
| 50 kg (110 lb) | 90 g | 100 g | 110 g | 80–110 g |
| 60 kg (132 lb) | 108 g | 120 g | 132 g | 96–132 g |
| 70 kg (154 lb) | 126 g | 140 g | 154 g | 112–154 g |
| 80 kg (176 lb) | 144 g | 160 g | 176 g | 128–176 g |
| 90 kg (198 lb) | 162 g | 180 g | 198 g | 144–198 g |
| 100 kg (220 lb) | 180 g | 200 g | 220 g | 160–220 g |
| 110 kg (243 lb) | 198 g | 220 g | 242 g | 176–242 g |
| 120 kg (265 lb) | 216 g | 240 g | 264 g | 192–264 g |
Rounded down to whole grams.
How much protein per meal?
The International Society of Sports Nutrition suggests 20 to 40 g of protein per meal, spread evenly every 3 to 4 hours. Splitting your daily total over four meals, or three plus a snack, usually lands in that range.
If your daily target is high, add a protein-rich snack, such as Greek yoghurt or cottage cheese, rather than one very large meal. For ideas, see the high-protein snacks ranked by protein per calorie, or these high-protein breakfast ideas with 20 g or more per serving.
See how much protein you have left today
Type what you ate in one sentence and FitDiary works out the protein in it. Ask ‘how much protein do I still need today?’ and it answers from what you’ve logged.
See how the FitDiary calorie counter works.
Frequently asked questions
How do I calculate how much protein I need?
Multiply your weight in kg by a factor for your goal: about 1.8 g to maintain, 2.0 g to lose weight and 2.2 g to build muscle. In pounds, use roughly 0.8, 0.9 and 1 g per lb. The calculator above does it for you.
How much protein does a 150-pound woman need?
150 lb is about 68 kg. If she exercises, the research range is 108 to 149 g a day. To lose weight, the calculator suggests 136 g; to maintain, 122 g. The adult RDA would be 54 g.
Is 100 g of protein a day enough for a woman?
It depends on her weight. For a woman who weighs 62.5 kg, 100 g is 1.6 g per kg, the lower end of the range for people who exercise. A lighter woman would be well covered; a heavier one who trains may need more.
Do I need 1 gram of protein per pound of body weight?
Not usually. 1 g per lb is 2.2 g per kg, the top of the research range. For most people who exercise, gains level off around 0.7 g per lb (1.6 g per kg); 1 g per lb is the upper end.
How much protein can you absorb in one meal?
This is less about absorption than about building muscle: the International Society of Sports Nutrition suggests 20 to 40 g per meal, spread over the day, rather than eating most of your protein in one go.
Do I need more protein when I’m losing weight?
Many people aim higher when they eat less, to help keep muscle. That’s why the app uses 2.0 g per kg for weight loss and 1.8 g to maintain. Strength training helps too.
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