Free Tool
Protein Calculatorfor Weight Loss
Your daily protein range and calorie target, from the same deterministic engine that powers Metriq's coaching.
Enough protein in a calorie deficit is what makes the weight you lose fat instead of muscle. How much protein you need to lose weight covers the research; this calculator turns it into your number.
On a GLP-1 medication? Use the GLP-1 protein calculator, which uses a gentler deficit.
How the numbers are calculated
Resting energy comes from the Mifflin-St Jeor equation (Mifflin, St Jeor et al., American Journal of Clinical Nutrition, 1990, the standard clinical estimate), scaled by a standard activity multiplier (1.2 sedentary through 1.9 athlete) to estimate your daily maintenance calories.
The calorie target is a 20% fat-loss deficit from that maintenance number. No target is ever set below a 1,200 kcal safety floor, and it's shown as a ±5% range, because a single exact number implies more precision than any estimate has.
Protein is a band, not a point: 0.8 to 1.1 g per pound of body weight (about 1.8 to 2.4 g per kg). The low end sits inside the range research ties to keeping muscle in a deficit. The high end matches the higher-protein group in a controlled trial where people in a large deficit, lifting hard, gained lean mass while losing fat at 2.4 g per kg (Longland et al., American Journal of Clinical Nutrition, 2016).
The full app goes further than this tool can: it folds in body-fat readings (which lower the protein basis when body fat is high), your food preferences and exclusions, wearable energy data, and weekly weigh-ins, and it adjusts the targets as your body changes. This page is the honest first pass, not the protocol.
How much protein do I need to lose weight?
Research on keeping muscle while losing fat points to roughly 1.6 to 2.2 g of protein per kg of body weight, about 0.7 to 1 g per pound. A 2018 meta-analysis found the muscle benefit of extra protein, alongside resistance training, levels off around 1.6 g per kg, with an upper bound near 2.2 (Morton et al., British Journal of Sports Medicine). This calculator gives a band of 0.8 to 1.1 g per pound of current weight: the low end is where muscle is protected, the high end is where the result is optimised.
Should I use my current weight or my goal weight?
This calculator uses current weight, which is what Metriq's engine does when it has no body-fat reading. If you have a lot of weight to lose, a per-pound target on current weight can run high; the full app switches to an estimated target body weight when body fat is above 30%, and our protein guide uses goal body weight for the same reason.
Is this medical advice?
No. These are nutrition estimates from your own inputs, not medical care, and not a substitute for it. If you have a medical condition, are pregnant, or take medication, talk to your doctor before changing how you eat.
Protein is one of three levers. The other two, deficit size and resistance training, are in how to lose fat without losing muscle.
The fine print, in plain words
These numbers are estimates computed from your own inputs, in your browser. Nothing you enter here is stored or sent anywhere. They are general nutrition guidance, not medical care, and not a substitute for it.
For a medical condition, pregnancy, prescription medication, or individualized clinical nutrition advice, talk to an appropriate healthcare professional.