About the Protein Calculator
This protein calculator estimates how many grams of protein you should eat each day. It multiplies your body weight by an evidence-based intake for your situation — from the 0.8 g per kilogram Recommended Dietary Allowance for sedentary adults up to about 1.6–2.4 g/kg for people strength training or dieting to lose fat while keeping muscle.
You also get a sensible range rather than a single number, a per-meal amount for the number of meals you eat, and the share of your daily calories that protein would make up. That makes it easy to check whether a meal plan, macro split or protein supplement actually fits your needs.
Targets are based on total body weight, which works well for most people. If you carry a lot of excess body fat, entering your goal weight instead of your current weight gives a more realistic number. People with kidney disease or on a protein-restricted diet should follow their clinician’s advice rather than these general targets.
With the default inputs, the daily protein target is 139 g/day. Change any value above to recalculate instantly.
How to use the protein calculator
- 1Choose US or metric units and enter your body weight.
- 2Pick the goal or situation that fits you best.
- 3Enter how many meals you eat per day.
- 4Optionally enter your daily calories to see protein as a percentage.
- 5Use the daily target and per-meal amount to plan meals and snacks.
Formula and method
Protein needs scale with body weight. The Recommended Dietary Allowance of 0.8 g/kg covers basic needs for most sedentary adults. Position stands from sports nutrition bodies suggest 1.4–2.0 g/kg for exercising people, with up to about 2.2 g/kg for maximal muscle gain and 1.6–2.4 g/kg to protect lean mass during a calorie deficit. Older adults are commonly advised 1.0–1.2 g/kg, and the RDA rises to about 1.1 g/kg in later pregnancy.
The calculator uses a typical target within the range for your goal and also shows the low and high ends of that range. Protein supplies about 4 kcal per gram, which is used to show its share of your daily calories. Weight is converted from pounds using 1 lb = 0.4536 kg.
- g/kg
- Grams of protein per kilogram of body weight per day
- 4
- Approximate kcal per gram of protein
Worked examples
170 lb lifter building muscle, 4 meals, 2,400 kcal
170 lb is 77.1 kg. At 1.8 g/kg that is about 139 g of protein a day (range 123–170 g), or about 35 g at each of 4 meals. At 4 kcal per gram it supplies about 555 kcal, roughly 23% of 2,400 kcal.
60 kg sedentary adult, 3 meals
The RDA of 0.8 g/kg gives 60 × 0.8 = 48 g of protein a day — 16 g per meal over three meals — which is only about 11% of 1,800 kcal.
90 kg person dieting to lose fat, 5 meals
At 2.0 g/kg a 90 kg dieter aims for 180 g of protein (range 144–216 g), 36 g per meal. That is 720 kcal, or 36% of a 2,000 kcal diet — high, but typical when dieting to protect muscle.
Frequently asked questions
How much protein do I need per day?+
The RDA for adults is 0.8 g per kg of body weight (about 0.36 g per lb), which is roughly 55 g for a 70 kg person. Active people and those building muscle generally benefit from 1.4–2.2 g/kg.
Is 1 gram of protein per pound too much?+
One gram per pound is about 2.2 g/kg, the upper end of what research shows is useful for building muscle. It is safe for healthy people, but most will get the same results from 1.6 g/kg (0.7 g per lb).
How much protein can the body absorb in one meal?+
Your body absorbs virtually all the protein you eat; the question is how much it uses for muscle building at once. About 20–40 g per meal (around 0.4 g/kg) maximises the muscle-building response, so spreading intake over 3–5 meals is sensible.
Should I use my current or goal weight?+
Use current weight if you are near a healthy weight. If you have a lot of body fat to lose, use your goal weight or lean body mass, because body fat does not need protein and current weight would overstate your needs.
Can eating too much protein be harmful?+
For healthy adults, intakes up to about 2 g/kg appear safe. People with chronic kidney disease should limit protein as advised by their doctor. Very high protein diets can also crowd out fibre-rich carbohydrates.
This tool gives general estimates and is not medical advice. Talk to a doctor or qualified professional about your health, diet or training.