How Much Protein Do You Need?

Protein requirements are usually quoted as a single confident number, which is part of why the advice you hear varies so wildly. The honest version is that your needs depend on your body weight and on how much you train — and that the answer is a range rather than a point.

Needs scale with body weight

Protein targets are expressed per kilogram of body weight, not as a flat daily figure. A 55 kg person and a 95 kg person doing the same training don't need the same amount, so any recommendation quoted as "70 g a day" is really a recommendation for one particular body.

The three tiers our Protein Intake Calculator uses:

The 0.8 g/kg baseline is the RDA from the U.S. and Canadian Dietary Reference Intakes, published by the National Institutes of Health. The higher figures for active people come from the International Society of Sports Nutrition's 2017 position stand on protein and exercise.

A worked example

For someone weighing 68 kg:

Sedentary:   0.8 x 68              = 54.4 g/day
Moderate:    1.0 x 68 to 1.2 x 68  = 68 to 81.6 g/day
Athlete:     1.2 x 68 to 2.0 x 68  = 81.6 to 136 g/day

The gap between the bottom and top of that table is substantial — roughly two and a half times more protein at the top of the athlete range than at the sedentary baseline. Which tier you belong in matters far more than precision within a tier.

If you enter your weight in pounds, the calculator converts to kilograms before applying the figures, so the result is the same either way.

What the RDA baseline actually means

The 0.8 g/kg figure is widely quoted and widely misunderstood. It is set as the amount sufficient to meet the needs of most healthy adults — a floor for preventing deficiency, not a target optimised for building muscle, preserving lean mass while dieting, or supporting heavy training.

That is why it sits at the bottom of the table rather than in the middle. If you train, the baseline is not wrong, it is just answering a different question than the one you are asking.

Choosing your tier honestly

The same trap as activity levels elsewhere on the site applies here: most people place themselves a tier higher than their actual training justifies.

• Sedentary — little or no regular exercise. The RDA baseline applies.
• Moderately active — regular exercise that is not structured strength or endurance training.
• Strength or endurance athlete — consistent, structured training. This is the tier that genuinely benefits from the higher intakes.

If you are between tiers, the ranges overlap enough that landing anywhere sensible in between is fine. This is not a calculation that rewards precision to the gram.

Where to go next

Why the result is a range rather than a single number is worth understanding — see why your protein target is a range. If you train seriously, protein for strength and endurance covers the top tier. And if you carry more or less muscle than average, body weight or lean mass explains which figure to base the calculation on.

Protein also needs to fit inside your total calories — the TDEE Calculator gives that number, and the Macro Split Calculator divides it up.

The bottom line

Multiply your body weight in kilograms by 0.8 if you are sedentary, 1.0–1.2 if you are moderately active, or 1.2–2.0 if you train seriously. Get your own figures from the Protein Intake Calculator, which shows the range, its sources, and its confidence level.