Protein Intake Calculator

How to use

This protein intake calculator converts a published weight-based reference into grams of protein per day. It provides the general adult Recommended Dietary Allowance (RDA) and a separate range for athletes. It does not build a diet, choose supplements or predict muscle gain. It is intended for generally healthy adults aged 19 or older, outside pregnancy, breastfeeding, medical conditions and prescribed nutrition plans.

Choose General adult for the RDA or Athlete for regular structured training such as endurance or resistance training. Occasional exercise does not have a separate multiplier here. Enter body weight, choose kilograms or pounds and press Calculate or Enter. The gray 70 kg example can be calculated immediately or replaced.

The main result is grams of protein per day. The basis line shows the coefficient and weight in kilograms, so you can check the arithmetic. Changing an input removes the confirmed result and disables copying until you calculate again. Copy result includes the basis and limitation. Clear removes your weight and result but retains your choices; an empty field can show its gray example again.

Method and meaning

The general adult RDA is 0.8 g/kg/day, so this mode returns one reference value. It is not a low-to-high range and is not a tolerable upper limit. The RDA describes an intake intended to meet the needs of nearly all healthy people in its reference group; it does not identify your individually optimal intake.

For athletes, the NIH Office of Dietary Supplements summarizes a range of 1.2–2.0 g/kg/day. It covers athletic training, but the calculator does not determine which point in that range suits a person. Training load, overall energy intake and personal circumstances matter. We do not invent separate fat-loss, bulking, age or recovery multipliers.

Pounds are converted with 1 lb = 0.45359237 kg. The calculation multiplies kilograms by the selected coefficient or both endpoints. It keeps intermediate precision and displays up to two decimal places. A displayed gram amount is a reference for total protein across the day, not the weight of a food portion or the amount of powder to buy.

Worked examples

General adult, 70 kg: 70 × 0.8 = 56 g/day. The output is a single RDA-based reference, not a 56–140 g range.

Athlete, 70 kg: 70 × 1.2 to 70 × 2.0 = 84–140 g/day. A weight of about 154.32 lb represents the same 70 kg after rounding and gives the same displayed range.

Scope and input checks

Use the two categories to understand the difference between an adult reference and a sports nutrition range. The athlete option is not a rule that every recreational exerciser should aim at the upper endpoint. A higher value is not automatically better, and the tool does not assess whether your existing food intake is sufficient.

Weight must be positive and within the software guard of 20–350 kg (approximately 44.09–771.62 lb). These limits catch obvious unit and entry errors; they do not mean the method is validated throughout that weight range. Check unit selection, especially after copying a weight from another source. Decimal points or decimal commas are accepted; thousands separators are not.

Children, pregnancy, breastfeeding, kidney disease and other medical nutrition needs are outside scope. A prescribed diet takes priority over this general reference. The page offers no food database, meal schedule, supplement dose or restriction plan.

Questions

Sources

• National Academies · Dietary Reference Intakes, reference tables
• NIH Office of Dietary Supplements · Exercise and Athletic Performance