Protein calculator

Start with the reference you mean to use, then multiply its grams per kilogram by body weight in kilograms. A protein calculator turns that rate into grams per day; it does not determine which rate is right for you.

Protein (g/day) = body weight (kg) × protein rate (g/kg/day)

For a range, calculate both ends. At 70 kg, 1.2–1.6 g/kg gives 84–112 grams per day. The adult RDA calculation gives 56 grams, while the exercise reference gives 98–140 grams. Those differences come from the chosen reference, not from a different conversion.

Pounds or kilograms

One pound is exactly 0.45359237 kilograms. This tool converts your entered weight when you change the unit, rather than keeping the same number with a different meaning. Results round to one decimal place; calculations use the underlying weight.

What the references mean

The 2025–2030 US dietary guidance gives a protein target of 1.2–1.6 g/kg/day. It is a dietary target, not the same quantity as the Recommended Dietary Allowance.

The Dietary Reference Intake tables use 0.8 g/kg/day for the general healthy-adult protein RDA. The RDA is a population reference intended to meet most healthy adults' needs. It is not an upper limit or a promise of an optimal intake for every purpose.

The International Society of Sports Nutrition position stand gives 1.4–2.0 g/kg/day for most healthy exercising individuals. Its exercise context matters; this tool does not assess your training or choose a personalized target.

Grams of protein are not grams of food

A daily total of 100 g protein does not mean 100 g of chicken, beans, or yogurt. Foods contain water and other nutrients too. Use a food's nutrition label or a reliable composition database to total protein across the foods you actually eat.

When this simple calculation is not enough

The tool uses the body weight you enter and does not select an ideal, adjusted, or lean body weight. Pregnancy, breastfeeding, childhood, older age, medical conditions, and a prescribed nutrition plan can require a different approach. A clinician or registered dietitian can help choose both the weight basis and rate when those circumstances apply.

Custom mode accepts rates up to 4 g/kg/day so you can reproduce arithmetic from another source. That input limit is a calculator limit, not an endorsed intake or a safe maximum.