How much protein do you need? This free protein calculator estimates your daily protein in grams from your weight, activity and goal – from the general RDA to muscle-building targets – with a per-meal guide.
Recommendations scale with body weight and how active you are. The general RDA is 0.8 g/kg; active people and those building muscle benefit from more.
General guidance for healthy people. Spreading protein across meals helps. If you have kidney disease or another medical condition, do not increase protein without medical advice – higher intakes aren’t suitable for everyone.
How the Protein Calculator Works
This calculator turns your body weight into a daily protein range in grams, using a per-kilogram intake band that depends on how active you are and what your goal is. It then breaks that range into a midpoint, a per-meal guide, and the calories that protein contributes.
Formula: Protein range (g/day) = Weight (kg) × low g/kg to Weight (kg) × high g/kg. Midpoint = (low value + high value) ÷ 2. Per meal = Midpoint ÷ 4. Calories from protein = Midpoint × 4 (since protein has about 4 kcal per gram).
- Body weight — your weight in kg or lb (toggle between units); the whole protein range scales directly from this.
- Activity & goal — a preset g/kg band: 0.8 g/kg for sedentary/general health, 1.2–1.6 g/kg for active/general fitness, 1.6–2.2 g/kg for building muscle or strength, 1.2–1.4 g/kg for endurance training, or 1.0–1.2 g/kg for an older adult preserving muscle.
Example Scenarios
| Weight | Activity / Goal | Protein Range | Midpoint | Per Meal (×4) |
|---|---|---|---|---|
| 70 kg | Sedentary / general health | 56 g/day | 56 g | 14 g |
| 70 kg | Active / general fitness | 84–112 g/day | 98 g | 25 g |
| 80 kg | Building muscle / strength | 128–176 g/day | 152 g | 38 g |
| 60 kg | Endurance training | 72–84 g/day | 78 g | 20 g |
| 65 kg | Older adult, preserve muscle | 65–78 g/day | 72 g | 18 g |
Protein Calculator FAQ
How much protein do I need per day?
It depends mainly on body weight and activity level. A common general reference is around 0.8 g per kg for sedentary adults, rising to 1.2–1.6 g/kg for active people and 1.6–2.2 g/kg for those building muscle through resistance training.Why does the calculator show a range instead of one number?
Protein needs vary within a category depending on training intensity, goals and individual factors, so a range (like 1.2–1.6 g/kg) is more realistic than pretending there’s one exact correct number. The midpoint is a reasonable single target if you want one.Is more protein always better for building muscle?
No — intake generally only helps up to a point, after which extra protein is mainly used for energy rather than additional muscle building. The building-muscle preset here already reflects a commonly cited higher-intake band.Can I eat too much protein?
For most healthy adults, intakes within these ranges are considered reasonable, but very high, sustained protein intake isn’t appropriate for everyone. Anyone with kidney disease or another medical condition should get personalized advice before increasing protein intake.Why does the calculator split protein into per-meal amounts?
Spreading protein across multiple meals rather than eating it all at once is a commonly recommended approach for muscle protein synthesis. Dividing your midpoint target by four gives a rough per-meal guide across four meals or snacks.Does the calculator account for older adults differently?
Yes, there’s a separate preset for older adults aiming to preserve muscle (1.0–1.2 g/kg), reflecting general guidance that slightly higher intakes than the base sedentary level can help offset age-related muscle loss.Related Calculators
Protein is just one piece of your daily nutrition — the macro calculator builds out your full protein, carb and fat targets, while the muscle mass calculator can help you track progress if you’re eating to build muscle. If you follow a plant-based diet, the vegan protein calculator is worth a look too.