Free Protein Intake Calculator
Estimate how many grams of protein to eat per day based on your body weight and your goal — from the basic dietary minimum up to a hard-training athlete's intake.
70.0 kg × 0.8 g/kg = 56 g/day.
The lower end meets the basic Recommended Dietary Allowance; the upper end suits hard-training athletes or a fat-loss phase. General information, not personalized medical advice.
Estimate only. This tool is for general information only and is not medical advice or a diagnosis. Results are estimates based on the formula shown. Consult a qualified healthcare professional for guidance about your own situation.
Quick answer
Your daily protein target is your body weight in kilograms multiplied by a grams-per-kilogram factor set by your goal: about 0.8 g/kg for sedentary adults (the RDA), 1.2 g/kg if generally active, 1.6 g/kg to build muscle, and around 2.0 g/kg for athletes or a fat-loss cut. For example, a 70 kg person needs 56 g/day at 0.8 g/kg and 112 g/day at 1.6 g/kg.
Formula & method
Daily protein (grams) = body weight in kilograms × a grams-per-kilogram factor chosen by goal and activity.
Examples
- Input
- weight = 70 kg, goal = 0.8 g/kg
- Result
- 56 g protein/day
- Why
- 70 × 0.8 = 56. This is the basic Recommended Dietary Allowance to prevent deficiency in an inactive adult.
- Input
- weight = 70 kg, goal = 1.6 g/kg
- Result
- 112 g protein/day
- Why
- 70 × 1.6 = 112. Resistance-training adults aiming to add muscle commonly target roughly 1.6 g/kg.
- Input
- weight = 90 kg, goal = 2.0 g/kg
- Result
- 180 g protein/day
- Why
- 90 × 2.0 = 180. Hard-training athletes and people in a fat-loss phase sit near the top of the range.
- Input
- weight = 154 lb, goal = 1.2 g/kg
- Result
- 84 g protein/day
- Why
- 154 ÷ 2.20462 = 69.85 kg, then 69.85 × 1.2 = 83.8, which rounds to 84 g/day.
When to use this tool
- Setting a daily protein goal for a muscle-building, fat-loss, or general-fitness diet.
- Planning meals or a grocery list so each day reaches a sensible protein total.
- Comparing how your needs change as your goal shifts from sedentary maintenance to active training.
- Giving a starting point for a conversation with a dietitian or healthcare professional.
Common mistakes
- Using the 0.8 g/kg RDA as a target instead of a floor. It is the minimum to avoid deficiency in sedentary people, not the optimal amount for someone who trains.
- Confusing grams of protein with grams of a protein-rich food. A 100 g chicken breast contains roughly 30 g of protein, not 100 g, so count the protein content, not the food weight.
- Entering weight in pounds while the unit is set to kilograms (or vice versa). 154 lb is about 70 kg, so the two settings give very different targets — pick the matching unit first.
- Assuming far more protein automatically builds more muscle. Beyond roughly 1.6–2.2 g/kg, extra protein gives little added muscle benefit for most people.
Frequently asked questions
How much protein do I need per day?
It depends on your body weight and goal. Multiply your weight in kilograms by 0.8 (sedentary minimum), 1.2 (active), 1.6 (building muscle), or about 2.0 (athlete or fat-loss cut). For a 70 kg person that is 56 to 140 grams per day.
Where does the 0.8 g/kg figure come from?
0.8 grams per kilogram is the U.S. Recommended Dietary Allowance (RDA) for protein in adults. It is the minimum needed to meet the requirements of most healthy, sedentary people, not a performance or muscle-building target.
How much protein should I eat to build muscle?
Research on resistance-trained adults generally supports roughly 1.6 grams per kilogram of body weight per day, with little extra benefit much beyond about 2.2 g/kg. This tool uses 1.6 g/kg for the muscle-building option.
Should I use my current weight or goal weight?
Most general guidance uses current body weight. People with a high body-fat percentage sometimes base the figure on lean body mass or a target weight to avoid overestimating; this calculator uses the weight you enter.
Can I just enter my weight in pounds?
Yes. Switch the unit to pounds and the tool converts to kilograms automatically using kg = lb ÷ 2.20462 before applying the grams-per-kilogram factor.
Is more protein always better?
No. Beyond the amount your body can use for muscle repair, extra protein is mostly used for energy or stored. Very high intakes offer little added benefit for most people, and those with kidney disease should follow a clinician's advice.
Is this medical advice?
No. This tool gives general nutritional estimates based on common guidelines. It is not personalized medical or dietary advice — consult a qualified healthcare professional or registered dietitian for individual needs.
Sources & references
- U.S. National Academies — Dietary Reference Intakes for Protein (RDA 0.8 g/kg)
- Morton et al., British Journal of Sports Medicine — Protein supplementation and resistance training (~1.6 g/kg)
- Mayo Clinic — Protein in your diet
External references open in a new tab. We are independent and not affiliated with these organizations.
Disclaimer
This tool is for general information only and is not medical advice or a diagnosis. Results are estimates based on the formula shown. Consult a qualified healthcare professional for guidance about your own situation.
- ✓ Free to use
- ✓ No sign-up required
- ✓ Runs entirely in your browser — nothing is uploaded.
- ✓ Formula and method shown above
Provided “as is” for general information only — results may be inaccurate, so verify before you rely on them. No warranty; use at your own risk.
Built and reviewed by HIFreeTools against the formula shown above and any authoritative references cited on this page. See our methodology and editorial standards.
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