Protein for Lifters Calculator
Adequate protein intake is the most important dietary variable for strength athletes seeking to build or maintain muscle mass. The International Society of Sports Nutrition (ISSN) and the American College of Sports Medicine (ACSM) both recommend 1.6 to 2.2 grams of protein per kilogram of body weight per day for resistance-trained athletes. This calculator shows the minimum (1.6 g/kg), optimal (2.0 g/kg), and maximum evidence-based (2.2 g/kg) daily protein targets, along with an estimate of how many grams to target per meal if eating 4 to 5 meals per day.
Protein target formula
Daily protein (g) = body weight (kg) × protein factor (g/kg)
Minimum: 1.6 g/kg | Optimal: 2.0 g/kg | Maximum: 2.2 g/kg
For an 80 kg lifter: minimum = 80 x 1.6 = 128 g/day; optimal = 80 x 2.0 = 160 g/day; maximum = 80 x 2.2 = 176 g/day. These targets are from the ISSN Position Stand on protein and exercise (Stokes et al., 2018) and the ACSM/AND/DC joint position statement on nutrition and athletic performance (2016).
Tips for meeting protein targets
- Aim for 20 to 40 g of protein per meal from high-quality sources: lean meat, poultry, fish, eggs, or dairy.
- Post-workout protein consumption within 2 hours of training is beneficial but not critical if daily totals are met.
- Leucine triggers muscle protein synthesis; aim for at least 2 to 3 g of leucine per meal (roughly 30 g of whey or chicken).
- Distribute protein evenly across 4 to 5 meals rather than concentrating it in one or two meals for optimal synthesis.
- Whole food sources are preferable; supplements are convenient but not superior to food protein.
Protein for lifters calculator: frequently asked questions
How much protein do strength athletes need?
The International Society of Sports Nutrition (ISSN) position stand recommends 1.4 to 2.0 g/kg/day for most exercising individuals, with 1.6 to 2.2 g/kg/day being optimal for maximizing muscle protein synthesis in resistance-trained athletes. Some research suggests up to 3.1 g/kg/day may be safe and potentially beneficial during aggressive cutting phases.
Is more protein always better for muscle building?
No. Research indicates a ceiling effect: consuming protein above approximately 2.2 g/kg/day provides no additional muscle-building benefit in most situations. Excess protein is used for energy or stored as fat. The ACSM notes that protein needs are best met through whole food sources and that supplementation is rarely necessary if food intake is adequate.
Does protein timing matter?
Yes, but less than total daily intake. The ISSN recommends consuming 20 to 40 g of high-quality protein every 3 to 4 hours throughout the day to maximize muscle protein synthesis. Post-exercise protein consumption (within 2 hours) is particularly beneficial. Pre-sleep protein (casein) also supports overnight muscle recovery.
What protein sources are best for muscle building?
Complete protein sources containing all essential amino acids are most effective. These include lean meats, poultry, fish, eggs, dairy, and soy. Whey protein is particularly fast-digesting and leucine-rich, making it popular post-workout. A leucine intake of 0.7 to 3.0 g per meal triggers the mTOR pathway for muscle protein synthesis.
Should protein intake be based on total body weight or lean body mass?
For individuals with moderate body fat (under 20 to 25%), total body weight is practical and accurate enough. For individuals with higher body fat, basing protein on lean body mass or ideal body weight prevents overestimation. The calculator uses total body weight with a note on this adjustment.
Official sources
- Stokes, T. et al. (2018). Recent perspectives regarding the role of dietary protein for the promotion of muscle hypertrophy with resistance exercise training. Nutrients, 10(2), 180. Published via: NIH PubMed Central.
- American College of Sports Medicine Position Stand: Nutrition and Athletic Performance: acsm.org.
- International Society of Sports Nutrition: issn.net.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.