Protein Intake Calculator: How Much Protein Do You Need?

The current tool multiplies weight by 0.8–1.2 g/kg for sedentary, 1.0–1.8 for lightly active, 1.2–2.0 for moderately active, 1.4–2.2 for very active, and 1.6–2.4 for extra active. Results are rounded to whole grams per day.

These five bands are product assumptions. We have not identified a primary guideline supporting this exact five-level mapping, so they are labelled illustrative rather than attributed to an institution. Exercise category alone is not enough to prescribe a protein intake.

The Dietary Reference Intake (DRI) tables list a protein Acceptable Macronutrient Distribution Range (AMDR) of 10–35% of energy for adults aged 19 and over. The tool converts each end using protein grams/day = estimated daily energy × energy fraction ÷ 4. [1]

This broad energy-share range is not a sport-specific prescription or a safety upper limit. Any error in the estimated calories carries into the gram range.

The 2007 expert report gives an adult safe intake level of 0.83 g/kg/day. Here, “safe level” concerns meeting protein requirements across a population; it is not a toxicity threshold, an individual minimum, or an optimal muscle-building target. [2]

At 70 kg, the calculation is 70 × 0.83 = 58.1 g/day, displayed as 58 g. For comparison, an illustrative 2,000 kcal/day energy reference gives 50–175 g at 10–35%. The figures differ because their definitions differ.

Resting kcal/day = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) + coefficient. The coefficient is +5 for the male equation and −161 for the female equation. Weight in pounds is divided by 2.20462; total height in inches is multiplied by 2.54.

The tool multiplies resting energy by 1.2, 1.375, 1.55, 1.725, or 1.9 for its five activity categories. These are approximate calculator factors, not activity coefficients validated by the original Mifflin study. That study supports the resting-energy equation, not a protein prescription. [3]

For a 35-year-old male, 80 kg and 180 cm, sedentary: resting energy is 1,755 kcal/day and estimated daily energy is 2,106 kcal/day. Its 10–35% protein conversion gives about 53–184 g/day; the custom weight band gives 64–96 g/day, and the WHO reference gives 66 g/day.

These are general adult references, not guidance for children, pregnancy, breastfeeding, kidney disease, recovery from illness, or other clinical circumstances. The resting-energy equation was developed in adults aged 19–78; a wider accepted input range is not evidence of validation outside that sample.

Training demands, total energy intake, protein quality, and health circumstances may change the appropriate plan. A qualified dietitian can help interpret a suitable target rather than simply choosing the largest number.

This calculation runs locally without AI or an AI usage quota. The result is not automatically saved to the Shelog app.