Protein Calculator
Work out how much protein you need each day, in grams, for your goal.
Runs in your browser — nothing is sent or saved.
How to work out your protein
- Pick metric or imperial and enter your body weight.
- Choose the goal that matches what you are doing.
- Read your daily protein target in grams.
- Copy the link to save or share it.
How much protein do I need
Protein needs scale with body weight, so this protein calculator works in protein per kg of body weight and multiplies by your weight to give grams of protein per day. The floor is the RDA, set to prevent deficiency in a sedentary adult. Anyone training, trying to build muscle, or losing fat while keeping muscle generally needs more than that floor, which is why the tool shows a range by goal rather than one figure.
Protein targets by goal
| Goal | Grams per kg |
|---|---|
| Sedentary (RDA baseline) | 0.8 |
| Generally active / fitness | 1.2 to 1.6 |
| Build muscle | 1.6 to 2.2 |
| Lose fat, keep muscle | 1.6 to 2.4 |
| Endurance training | 1.2 to 1.4 |
Sources: the 0.8 g/kg RDA is from the Dietary Reference Intakes, National Academies of Sciences (Institute of Medicine). The higher training ranges follow the International Society of Sports Nutrition (ISSN) position stand on protein and exercise, which recommends roughly 1.4 to 2.0 g/kg for building and maintaining muscle.
Why active people need more
The RDA of 0.8 g/kg is the amount that stops a sedentary adult becoming deficient. It was never meant as an optimal target for someone lifting weights or running. Training breaks down muscle protein, and eating more helps rebuild it, which is why the sports-nutrition ranges sit well above the RDA. Spreading protein across the day, rather than one large serving, also helps.
An estimate, not medical advice
These are general ranges for healthy adults. People with kidney disease or other conditions may need to limit protein, so this is not advice for them. Talk to a doctor or dietitian before making a big change, especially if you have a health condition.
FAQ
How much protein do I need per day?
It depends on your weight and goal. A generally active person needs about 1.2 to 1.6 grams per kg of body weight, so a 70 kg person lands near 84 to 112 grams a day. Building muscle pushes that higher.
How much protein to build muscle?
Most evidence supports roughly 1.6 to 2.2 grams per kg of body weight when training to build muscle, alongside enough total calories. More than that gives little extra benefit.
Is the RDA of 0.8 g/kg enough?
It is enough to prevent deficiency in a sedentary adult, but it is a minimum, not a target for anyone active. Training raises the requirement.
Can I get too much protein?
For healthy people, high protein intakes are generally safe, though there is little benefit above the ranges shown. People with kidney problems should follow medical advice instead.
Are my details private?
Yes. Everything is calculated in your browser and nothing you enter is uploaded or saved.