Protein Calculator
This protein calculator estimates how many grams of protein you need each day from your body weight, your age and how you train. You get a daily target, a low-to-high range, the amount per meal and the calories that protein supplies. The ranges come from the US Recommended Dietary Allowance and from sports nutrition research, so you can see where the minimum ends and where extra protein starts to matter.
Updated
Results
- Low end (g/day)
- High end (g/day)
- Low end (g per kg)Per kilogram of body weight; 1 kg = 2.2 lb
- High end (g per kg)Per kilogram of body weight
- Protein per meal (g)Daily target ÷ meals
- Calories from protein (kcal)4 kcal per gram
Results are estimates. See the methodology below.
How to use the protein calculator
- Keep US units and enter your weight in pounds, or switch to kilograms.
- Enter your age (18 or older).
- Choose the activity level that fits a normal week: mostly sedentary, regular exercise or sport, or strength training aimed at building muscle.
- Optional: open More options and change the number of meals (4 by default) to split the total.
- Read your daily protein in grams, the range for your activity, the grams per meal and the calories from protein.
How the calculator works
Protein needs scale with body weight, so the calculator first converts pounds to kilograms (1 lb = 0.4536 kg) and then multiplies by a factor in grams per kilogram per day:
| Activity level | g per kg per day | g per lb per day |
|---|---|---|
| Mostly sedentary | 0.8 (1.0 at 65+) | 0.36 (0.45 at 65+) |
| Regular exercise or sport | 1.2–2.0 | 0.54–0.91 |
| Strength training for muscle gain | 1.6–2.2 | 0.73–1.0 |
- 0.8 g/kg is the RDA set by the National Academies for adults: enough for nearly all healthy people, not an optimal or athletic intake.
- 1.2–2.0 g/kg is the range in the 2016 joint position statement of the Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine.
- 1.6 g/kg comes from a 2018 meta-analysis by Morton and colleagues (49 trials, 1,863 people): beyond about 1.62 g/kg, extra protein added no further gain in lean mass from resistance training. The calculator extends the range to 2.2 g/kg to allow for individual differences.
- 1.0 g/kg from 65 follows the German Nutrition Society (DGE). The US RDA does not change with age, so 0.8 g/kg is the US minimum at any adult age.
The main result is the middle of your range. Per meal = daily grams ÷ meals; calories = grams × 4 kcal.
Examples
Office worker, 35, 160 lb, mostly sedentary
160 lb is 72.6 kg, and 72.6 × 0.8 gives 58 g of protein a day: about 15 g per meal over four meals, or 232 kcal.
Woman, 29, 145 lb, runs and lifts several times a week
The range is 79 to 132 g (1.2–2.0 g/kg), with a midpoint of 105 g, 26 g per meal and 421 kcal.
Man, 27, 185 lb, lifting to build muscle
At 1.6–2.2 g/kg he gets 134 to 185 g, a midpoint of 159 g and 40 g per meal across four meals (638 kcal).
Retiree, 70, 150 lb, sedentary
From 65 the calculator uses 1.0 g/kg: 68 g a day, or 23 g per meal across three meals.
Reading your result
The Dietary Guidelines for Americans 2025–2030 suggest aiming for 1.2 to 1.6 g of protein per kg of body weight a day, so the sedentary result is a floor, not a target. If you exercise, the midpoint is a sensible starting point; move toward the top of the range if you are cutting calories or training hard.
Spreading protein matters too: the 2016 position statement recommends about 0.3 g/kg after key workouts and at regular intervals of three to five hours across meals. For a 185 lb lifter that is roughly 25 g per meal.
Talk to your doctor or a registered dietitian first if you have kidney disease, are pregnant or breastfeeding (needs rise, especially later in pregnancy), are under 18, or have or have had an eating disorder. This tool is not designed for those situations.
Frequently asked questions
How much protein do I need a day?
The RDA is 0.8 g per kg (about 0.36 g per pound), which is 58 g for a 160 lb adult. Active people usually need more: 1.2–2.0 g/kg, depending on how much and how hard they train.
How much protein do I need to build muscle?
A 2018 meta-analysis found that gains in lean mass from resistance training leveled off at about 1.6 g/kg (0.73 g per pound) per day. Eating more than that added little extra muscle in the studies analyzed.
Should I use my current weight or my goal weight?
The calculator uses the weight you enter. If you carry a lot of excess body fat, your current weight can overstate your needs; entering a realistic goal weight gives a more reasonable number.
Is too much protein bad for you?
No official upper limit exists. The European Food Safety Authority found too little data to set one and considers twice the reference intake safe for adults. People with kidney disease are different and should follow their doctor’s advice.
How much protein can I absorb in one meal?
Sports nutrition guidance does not set a hard per-meal limit. It suggests about 0.3 g/kg per meal, repeated every three to five hours, which is the kind of split the per-meal result gives you.
Do older adults need more protein?
In the US the RDA stays at 0.8 g/kg at every adult age. Germany’s DGE recommends 1.0 g/kg from 65, which this calculator uses. Ask your doctor what suits you.
Sources
- National Academies Press — Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids
- Academy of Nutrition and Dietetics, Dietitians of Canada, ACSM — Nutrition and Athletic Performance (joint position, 2016)
- Morton RW et al. — Protein supplementation and resistance training-induced gains in muscle mass and strength (Br J Sports Med, 2018)
- American Family Physician — Dietary Guidelines for 2025–2030: Recommendations From the USDA and HHS (2026)
- EFSA — Scientific Opinion on Dietary Reference Values for protein (EFSA Journal, 2012)
- Deutsche Gesellschaft für Ernährung (DGE) — Reference values: protein
This calculator gives general estimates and is not medical or nutrition advice. It is not intended for kidney disease, pregnancy or breastfeeding, people under 18 or eating disorders; talk to a doctor or registered dietitian.