Protein for Weight Loss Calculator: How Much to Eat Without Losing Muscle
Eating in a calorie deficit? Get the higher protein target that helps preserve muscle while you lose fat: grams per day and per meal, the 1.6–2.4 g/kg range, per-pound figures and the share of your calories.
How it works
Daily protein = weight (kg) × grams per kg · Per meal = daily protein ÷ meals · Calories from protein = grams × 4 · Muscle-sparing range = 1.6–2.4 g/kg (2–3 × the 0.8 g/kg RDA) · 1 g/kg = 0.454 g/lb
When you eat below maintenance, the body can lose muscle as well as fat unless enough protein and resistance training signal it to keep lean tissue. The RDA of 0.8 g of protein per kilogram is a minimum for people who are not dieting. The International Society of Sports Nutrition (ISSN) puts most exercising people at 1.4–2.0 g/kg a day and notes that intakes two to three times the RDA, 1.6–2.4 g/kg, help preserve lean mass during energy restriction; leaner people and steeper cuts sit at the top of that band. If you have a lot of weight to lose, basing the target on your goal weight stops it from being inflated by body fat. The calculator multiplies the weight by the grams per kilogram you choose, splits the total across your meals, converts it to calories (4 kcal per gram) and, if you enter a calorie target, shows what share of it protein takes; the usual range for adults is 10–35% of calories, and high-protein diets often go above it. The ISSN suggests about 0.25 g/kg per meal, usually 20–40 g, spread every 3–4 hours.
Worked example
Default: 80 kg, current weight, 2.0 g/kg and 4 meals. The target is 80 × 2.0 = 160 g of protein a day, which supplies 160 × 4 = 640 kcal, or 32% of a 2,000 kcal target. Split over 4 meals that is 40 g per meal, against an ISSN per-meal guide of 0.25 × 80 = 20 g. The muscle-sparing range runs from 128 g (1.6 g/kg) to 192 g (2.4 g/kg), and 2.0 g/kg equals 0.91 g per pound. Basing it on a 70 kg goal weight instead gives 140 g a day.
Sources: ISSN position stand: protein and exercise (Jäger et al., 2017) · Calculator.net: Protein calculator (RDA and 10–35% of calories)
Frequently asked questions
How much protein should I eat to lose weight?
Most people in a calorie deficit do well on 1.6–2.4 g per kilogram of body weight a day (about 0.7–1.1 g per pound), which is two to three times the RDA. Around 2.0 g/kg is a common middle choice, with the top of the range for lean people on a steep cut.
Why more protein when cutting than when maintaining?
A calorie deficit raises the risk of losing muscle along with fat. Extra protein, paired with strength training, tilts the loss toward fat and helps keep the muscle that supports your metabolic rate. Protein is also filling, which makes a deficit easier to stick to.
Should I base it on goal weight instead?
If you carry a lot of excess fat, scaling protein to goal weight avoids an unrealistically high number. If you are close to a healthy weight, current body weight is a fine basis.
How much protein should I eat per meal?
About 0.25 g per kilogram of body weight, usually 20–40 g, every 3–4 hours is the ISSN guide. Eating more at once is fine; it just does not add much extra muscle-building effect at that meal.
Can I get too much protein?
For healthy kidneys, intakes in this range are well tolerated. Going far beyond 2.4 g/kg rarely adds benefit for body composition and crowds out other foods. People with kidney disease should ask their doctor first.
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Educational estimate only, not medical or dietary advice. Calorie and weight-change figures are population averages; individual results vary. Consult a doctor or registered dietitian before starting a weight-loss, fasting or exercise plan.