Protein Intake Calculator

When you eat in a calorie deficit to lose fat, your body is more willing to break down muscle for energy. Eating more protein pushes back against that — it's the single most important dietary lever for holding onto muscle while you lose fat. So the cutting setting in this calculator raises your target above maintenance, to a range of about 1.6 to 2.4 grams per kilogram of bodyweight with a target of 2.0 — the standard fat-loss range for resistance-trained dieters.

If you're already lean and dieting hard, the demand climbs higher still. Helms and colleagues' 2014 review of protein for lean, energy-restricted, resistance-trained athletes put the useful range at 2.3 to 3.1 grams per kilogram of lean mass — so when you're cutting with a body-fat percentage entered, the tool shows that contest-prep line alongside your main number. There's a bonus, too: protein is the most filling macronutrient, so a higher-protein diet tends to be easier to stick to when calories are tight. The catch is that protein only spares muscle if you give your body a reason to keep it — keep training hard while you cut.

A per-kilogram protein target multiplied by your total bodyweight works fine for most lifters. But it starts to overshoot at higher body-fat levels, because fat tissue barely uses protein — scaling the same per-kilogram number off a heavier total weight inflates the target beyond what your muscle actually needs.

To handle that honestly, this tool uses a simple cap: if you enter a body-fat percentage above 30%, it caps the reference weight at the weight you'd carry at 30% body fat — fat mass beyond that doesn't raise your protein needs, so the tool doesn't count it. Below 30%, or if you leave body fat blank, it uses your full bodyweight, because the difference is small enough not to matter. We show a note in your result whenever the cap kicks in, so you always know which reference weight you're looking at.

There's a flip side for lean dieters. If you're cutting and your body fat is below 30%, the tool adds a separate contest-prep line based on your lean mass — 2.3 to 3.1 grams per kilogram of lean mass, the range Helms and colleagues (2014) found for lean, energy-restricted, resistance-trained athletes. It's shown as extra context under your main number, not as the headline.

A little, but far less than the daily total. There's a popular idea that you should eat a set amount of protein per meal — often quoted as around 0.4 g/kg per sitting across several meals — to maximize muscle protein synthesis. It's a reasonable-sounding refinement, and spreading protein across three to five meals may give a small edge. But the evidence for it is weak, and it's nowhere near as important as simply hitting your daily number.

The per-meal view in your result is there for convenience — to turn your daily target into a rough per-meal figure you can actually plan around. Treat it as a guide, not a rule. If your schedule means two big protein hits some days and four smaller ones on others, that is completely fine as long as the day's total lands where it should.

For healthy people, yes. The long-standing worry that high protein damages your kidneys comes from advice given to people who already have kidney disease — and it doesn't transfer to healthy individuals. In people with normal kidney function, higher protein intakes in the range this tool suggests haven't been shown to cause kidney harm. Well-formulated high-protein diets are used routinely by athletes without issue.

The honest caveat: if you have a diagnosed kidney condition, or any other medical situation where protein matters, this general-purpose tool isn't the right guide — talk to your doctor or a dietitian, who can set a target for your specific situation. This is a fitness utility, not medical advice.

Your target is a per-kilogram protein factor multiplied by a reference weight. Each goal has a low/high band and an explicit headline target: maintenance 1.4–2.0 g/kg (target 1.6), gaining 1.6–2.2 g/kg (target 1.8), cutting 1.6–2.4 g/kg (target 2.0). The maintenance and gaining numbers come from the Morton et al. 2018 meta-analysis; the cutting range is the standard fat-loss band for resistance-trained dieters. When you supply a body-fat percentage above 30%, the reference weight is capped at the weight you'd carry at 30% body fat — because total-weight targets overshoot when a lot of that weight is fat. And if you're cutting with body fat below 30%, the tool adds a contest-prep line of 2.3–3.1 g/kg of lean mass (Helms et al. 2014). The headline is the goal's target; the low and high bracket it.

We deliberately ship a defensible range rather than a false-precision single number. Protein needs vary between people, and no calculator can measure your personal optimum — so the tool is a starting point to reason from, not a prescription to obey. This is a fitness utility, not medical or dietary advice; if you have a kidney condition or another medical concern, speak to a professional.

The calculation runs entirely in your browser. The tool's own usage events only ever send coarse buckets — a bucketed protein target and bodyweight range, your goal, and which basis was used — never your exact numbers. If you use the share button, your entered values are encoded into that link so the page can rebuild your result; that link then sits in your address bar like any other URL.