Protein Intake Calculator
Protein needs are best expressed as a range that depends on your goal, not a single number. This protein intake calculator multiplies your body weight in kilograms by a grams-per-kilogram factor you choose. The U.S. RDA is 0.8 g/kg — enough to prevent deficiency in a sedentary adult — while active people, those building muscle, and dieters keeping lean mass commonly aim for roughly 1.2 to 2.2 g/kg. Pick the factor that matches your goal and treat the result as a target range to plan meals around, not a strict requirement.
Calculate
Default result: 112 g
Protein Intake Calculator · Result
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Daily protein
154 lb × 1.6
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This calculator provides general estimates for educational purposes only and is not medical advice. Results are based on population formulas and may not reflect your individual circumstances. Consult a qualified healthcare professional before making changes to your diet, exercise, or health routine.
Reviewed by the calculators.dev team · Last updated 2026-06-23
Formula reviewed against U.S. Dietary Reference Intakes (RDA 0.8 g/kg) and sports-nutrition position stands (1.2–2.2 g/kg for active adults) — present as a range by goal
How to calculate
Enter your body weight and the protein factor for your goal: about 0.8 g/kg for the basic RDA, 1.2–1.6 for general activity, and 1.6–2.2 for muscle gain or dieting while training. The calculator multiplies the two. A 70 kg person at 1.6 g/kg needs 112 g/day; at the 0.8 RDA it is 56 g. Try a couple of factors to see your range, then spread the protein across meals — many people aim for 20–40 g per meal.
protein_g = body_weight_kg × factor, where factor is grams of protein per kilogram of body weight. Variables: body weight in kilograms and a goal-based factor (≈0.8 RDA up to ≈2.2 for athletes). The result is grams of protein per day. Because the right factor depends on activity, age, and goals, the output is best read as the centre of a range rather than an exact requirement.
Example calculation
A 70 kg (about 154 lb) person using a factor of 1.6 g/kg — a typical target for active people building or keeping muscle — needs 70 × 1.6 = 112 g of protein per day. Switching the factor to the 0.8 g/kg RDA gives 56 g, which shows how much the target depends on your goal.
- proteinG
- 112 g/day
Assumptions
- Protein targets are a range by goal (RDA 0.8 g/kg up to roughly 2.0–2.2 g/kg for athletes), so the result depends entirely on the factor you choose.
- The estimate uses total body weight; some guidance for higher-body-fat individuals uses lean mass or a target weight instead.
- It is a general guideline for healthy adults and does not account for kidney disease, pregnancy, or other conditions that change protein needs.
Common mistakes
- Using the 0.8 g/kg RDA as a performance target. The RDA prevents deficiency; active people and those building muscle usually need considerably more.
- Calculating protein from pounds with a per-kg factor. Convert weight to kilograms first, or the number will be off by more than double.
- Eating all the protein in one meal. Spreading it across the day (roughly 20–40 g per meal) supports muscle protein synthesis better than one large serving.
Frequently asked questions
How much protein do I need per day?
It depends on your goal. The RDA is 0.8 g per kg of body weight, general activity is around 1.2–1.6 g/kg, and muscle gain or dieting athletes often target 1.6–2.2 g/kg. Pick the factor that fits your situation.
Should I base protein on body weight or lean mass?
Total body weight works for most people. If you carry a lot of excess fat, some guidance suggests using lean mass or a target weight so the figure is not inflated. Either way, treat it as a range.
Can I eat too much protein?
For healthy adults, intakes in the common athletic range (up to about 2.2 g/kg) are generally considered safe. People with kidney disease or other conditions should follow medical advice rather than a general guideline.
Does protein timing matter?
Total daily protein matters most, but spreading it across meals — roughly 20–40 g each — helps muscle maintenance and growth more than concentrating it in a single meal.