Protein calculator
Estimate your daily protein range. Enter your body weight and choose a goal.
For healthy adults who strength train regularly.
How this protein calculator works
For building muscle or general fat loss, we multiply your body weight in kg by 1.6 and 2.2. At 80 kg, that gives 128–176 g per day. These are starting points for planning your meals, not precise measurements of what your body needs.
A meta-analysis of 49 resistance-training studies estimated that gains in fat-free mass levelled off around 1.6 g/kg/day on average. Its upper confidence bound was 2.2 g/kg/day. That bound describes uncertainty in the group estimate, not the amount that every person needs. ISSN guidance gives a broader 1.4–2.0 g/kg/day range for most people who exercise.
Changing between kg and lb keeps the same protein range.
Does fat loss change your protein needs?
Eating fewer calories can make it harder to retain muscle. Protein needs may rise, especially for lean lifters and larger calorie deficits. The muscle-gain meta-analysis did not study people in a calorie deficit, so it cannot establish an exact fat-loss target.
For experienced lifters who are already lean and dieting, select “Lose fat while already lean” and enter your estimated body-fat percentage. We subtract the estimated fat from your weight, then multiply the remaining fat-free mass by 2.3 and 3.1. At 80 kg and 15% body fat, that is 68 kg of fat-free mass and about 156–211 g of protein per day. This published range comes from a review of lean, trained athletes; it is not intended for everyone losing weight.
How accurate is the result?
The result is a guide, not an exact personal requirement. Body-fat estimates from home scales or visual comparisons can be inaccurate, and a different estimate changes the lean cutting result. If you do not know your body-fat percentage, choose “Lose fat while lifting” to use the weight-only starting range. At higher body-fat levels, even that range can overestimate your needs; a sports dietitian can help you set a target.
This is general guidance for healthy adults, not a target for children, pregnancy or a medical diet. It does not calculate calories, diagnose a condition or establish a safe maximum protein intake.
Common questions about daily protein
Do I need a different target on rest days?
Use the same daily starting range on rest days. Recovery continues between workouts, and this tool does not lower the target because you are not lifting today.
Do I need protein powder?
No. Count protein from all your food and any supplements together. Protein powder can be convenient, but it is not required to reach a daily target.
Which fat-loss option should I choose?
Choose “Lose fat while lifting” for a simple starting range based on body weight. Choose “Lose fat while already lean” if you have lifting experience, are dieting and have a body-fat estimate. That option uses your estimated fat-free mass. The research behind it included adults with more than 6 months of resistance training and body fat at or below 23% for men or 35% for women. These describe the people studied, not exact boundaries for protein needs.
Research behind the range
- Morton et al. (2018)
Meta-analysis of protein supplementation and resistance training in healthy adults who were not restricting calories.
- ISSN position stand (2017)
Sports-nutrition guidance on daily protein, training recovery and protein from food or supplements.
- Helms et al. (2014)
Review of protein during calorie restriction in lean, resistance-trained athletes. Its range uses fat-free mass.
- Longland et al. (2016)
A four-week trial comparing 1.2 and 2.4 g/kg/day during a large calorie deficit and intensive exercise in young men.