Protein Calculator
Find your daily protein target.
kg or lb
Results update as you type.
This calculator provides estimates based on population research. Results are not medical advice. Consult a qualified healthcare provider before making health or nutrition decisions.
How it works
Protein is the macronutrient your body uses to build and repair muscle, produce enzymes and hormones, and support immune function, and its daily requirement scales with body weight and how active you are. This protein calculator translates that principle into a gram target. The floor for a sedentary adult is the Recommended Dietary Allowance of about 0.8 g per kilogram, set to prevent deficiency, but that figure was never meant to optimise training or body composition. Once you exercise regularly, aim to build muscle, or diet while trying to keep muscle, the evidence points much higher, into the 1.2 to 2.2 g per kilogram range, with the upper end useful during aggressive fat loss. Those figures come from the International Society of Sports Nutrition position stand, which pooled controlled feeding and resistance-training studies to establish intakes that maximise muscle protein synthesis. A protein calculator built on that research gives athletes, lifters and dieters a target grounded in evidence rather than guesswork. Higher protein also aids fat loss by preserving lean mass in a calorie deficit and by keeping you fuller between meals. This protein calculator shows a recommended amount for your chosen goal plus a sensible range around it, so you can distribute the total across your meals in whatever way fits your routine and appetite.
grams = body weight (kg) × factor (0.8 general … 2.4 fat loss)
The gram target multiplies body weight in kilograms by a factor tied to your goal, because protein needs scale with the amount of lean tissue to maintain or build, which itself scales with body size. Sedentary maintenance sits near 0.8 g/kg, while training, muscle gain and dieting push the factor toward 1.6 to 2.4 g/kg to support repair and preserve muscle.
Source:International Society of Sports Nutrition position stand (2017)
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter body weight and goal.
- 2
Adjust the options
Adjust units if they apply — sensible defaults are already set.
- 3
Read your result
Daily protein updates instantly as you type — no button to press.
Frequently asked questions
How much protein do I need per day?
It depends on your goal. A sedentary adult needs about 0.8 g per kilogram of body weight to avoid deficiency, but active people benefit from 1.2 to 2.0, and those building muscle or dieting hard do best at 1.6 to 2.4. For a 70 kg person that spans roughly 84 to 168 grams a day. This tool sets the target from the goal you pick rather than a single blanket figure.
Can eating too much protein harm you?
For healthy adults, no. Intakes well above the RDA are safe and well tolerated, and the old worry that high protein damages healthy kidneys is not supported by evidence. The real ceiling is practical: beyond roughly 2.2 g per kilogram there is little extra benefit for muscle, and those calories are better spent elsewhere. People with existing kidney disease are the exception and should follow medical guidance.
Should protein be based on body weight or lean mass?
This tool uses total body weight for simplicity, which works well for most people. If you carry a lot of body fat, however, a target based on lean mass or goal weight is more accurate, because fat tissue has little protein requirement. In that case, calculating against your estimated lean body mass avoids setting a needlessly high figure. For lean and average builds, total weight is fine.
Does timing my protein across the day matter?
Total daily intake matters most, but spreading protein across three to five meals of 20 to 40 grams each does modestly improve muscle protein synthesis compared with one large serving. Aim for a protein source at each main meal rather than obsessing over exact windows. The post-workout anabolic window is far wider than once believed, so hitting your daily total is the real priority.
Can I hit these targets on a plant-based diet?
Yes, though it takes more planning. Plant proteins are often lower in the amino acid leucine and less complete individually, so combine varied sources such as legumes, soy, grains, nuts and seeds across the day. Aiming toward the higher end of the range compensates for slightly lower digestibility. Soy, lentils, tofu, tempeh and seitan make reaching a high gram target on a vegan diet very achievable.