Protein Intake Calculator

How to use the protein intake calculator

Enter your body weight and pick the goal that matches how you train, and the tool returns a target for daily protein in grams. Weight takes a kg/lb toggle, so use whichever unit you think in — the math runs on kilograms internally and converts for you. The defaults (70 kg, “Build muscle”) are there so you can see the tool work before you swap in your own numbers; on those defaults it returns 126 g a day. These figures are general, evidence-based ranges to aim for, not a prescription, and the page carries a medical-disclaimer line for that reason.

The goal sets a factor in grams of protein per kilogram of body weight, and that factor is the whole story behind the number. Sedentary uses 0.8 g/kg, General health 1.2, Endurance 1.4, Active 1.6, and Build muscle 1.8. Pick the one that honestly describes your week rather than the one you wish described it: someone who lifts seriously three or four times a week sits in the Active-to-Build-muscle band, while a desk job with little training sits near the bottom. Change the goal and the daily target moves with it, because the factor is doing all the work.

Read the main output as your daily protein target, then read it alongside the goal’s broader range rather than treating it as a single exact figure. The “Build muscle” setting lands on 126 g for a 70 kg person, but the strength-and-physique band as a whole runs roughly 1.6–2.2 g/kg — about 112–154 g at 70 kg — so anywhere in that window is reasonable, with the 1.8 figure sitting comfortably in the middle. Bodies, training loads, and goals vary, so the range is the honest way to think about it; the single number is just a sensible place to start inside that range.

It helps to think of the daily total as something to spread across the day, not hit in one sitting. The research on muscle protein synthesis points to dividing your intake across roughly three or four meals of about 20–40 g each, which supports muscle better than loading nearly all of it into one large serving. So once the tool gives you a daily target, a useful next step is dividing it by your number of meals to get a per-meal goal — 126 g over four meals is a little over 30 g a meal, squarely in that range.

Use the number as a target to build meals around, then check it against real food. Lean meat, fish, eggs, dairy, legumes, tofu, and protein powders are all dependable sources, and most people reach a moderate target through food alone before any powder enters the picture. If your goal or training changes, come back and re-pick the goal — the factor, and therefore the target, will shift to match. Treat the output as a starting range to refine over weeks, not a fixed quota to chase to the gram.

The formula

The calculation is a single multiplication: your weight in kilograms times the grams-per-kilogram factor your goal sets. Weight entered in pounds is converted to kilograms first so the units line up, and the result is your daily protein target in grams:

daily protein (g) = weight kg × goal factor (g/kg)

Worked example with the defaults — a 70 kg person on the “Build muscle” goal (1.8 g/kg): 70 × 1.8 = 126 g a day. Swap the goal and only the factor changes: Sedentary (0.8) gives 70 × 0.8 = 56 g, General health (1.2) gives 84 g, Endurance (1.4) gives 98 g, and Active (1.6) gives 70 × 1.6 = 112 g. Change your weight and every figure scales in step, because the whole thing is one straight multiplication.

The 0.8 g/kg figure at the bottom is the RDA — the amount set to prevent deficiency in most healthy adults, a floor rather than an optimum, and it is not the target for people who train hard. Strength and physique athletes commonly aim higher, around 1.6–2.2 g/kg, with endurance athletes somewhat below that, which is why the goals above climb past the RDA. Distribution matters too: spreading protein across roughly three or four meals of about 20–40 g supports muscle protein synthesis better than one big serving. And on the common worry about kidneys — in people with healthy kidneys there is no good evidence that higher protein intake causes kidney damage; those with existing kidney disease are the exception and should follow their own medical advice.

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