Protein Intake Calculator
Protein is the one macro worth getting right — the target scales with your bodyweight and your goal.
Work out how much protein to eat a day, in grams, from your bodyweight and goal. It uses the standard grams-per-kilogram guidelines — from the 0.8 g/kg RDA minimum up to 1.6–2.2 g/kg for building muscle — and splits your daily target across meals of about 25–40 g to make the most of each one.
General guidance from bodyweight and goal — not medical advice. Needs vary; anyone with kidney disease should get medical advice before raising protein, and follow your doctor's advice.
How your protein target is worked out
Grams per kilogram × bodyweight
Protein targets are set in grams of protein per kilogram of bodyweight a day. The calculator takes your weight and multiplies it by a g/kg figure chosen by your goal: 0.8 g/kg is the RDA minimum, about 1.2–1.6 g/kg for general fitness, 1.6–2.2 g/kg to build muscle, and 1.8–2.4 g/kg when losing fat and trying to keep muscle. Older adults (50+) sit at the higher end to protect against age-related muscle loss. You can also enter a custom g/kg to override the goal.
Split across your meals
It then divides your daily total by your number of meals. To make the most of each meal for muscle, aim for about 0.3 g/kg — roughly 25–40 g of protein per meal, enough to cross the "leucine threshold" that switches on muscle protein synthesis. Spreading protein evenly through the day tends to beat one big hit.
Worked example
An 80 kg adult building muscle at 1.8 g/kg: 80 × 1.8 ≈ 144 g of protein a day. Split across 4 meals, that is about 36 g per meal — comfortably over the ~25–40 g per-meal target that maximises the muscle-building response.
This is general guidance, not medical advice. Everyone's needs differ, and existing conditions matter: anyone with kidney disease should speak to a doctor before raising protein, and protein needs in pregnancy differ. Treat the number as a sensible target to aim near, then adjust to how you train, recover and feel.
How much protein you need — by goal
There is no single number that fits everyone. The right target depends on what you are training for, so pick the range that matches your goal and multiply by your bodyweight.
- Sedentary — 0.8 g/kg (RDA). The minimum to avoid deficiency in an inactive adult. About 64 g for an 80 kg person.
- General fitness — 1.2–1.6 g/kg. A solid range if you train a few times a week and want to stay healthy and lean.
- Build muscle — 1.6–2.2 g/kg. Enough building blocks to add muscle when paired with resistance training and enough energy.
- Fat loss (keep muscle) — 1.8–2.4 g/kg. Higher protein in a deficit preserves muscle and keeps you fuller. Consider basing this on a target or lean bodyweight if you carry a lot of fat.
- Older adult (50+) — toward the higher end. More protein helps counter the muscle loss that comes with ageing.
For most people the sweet spot for training and body composition sits somewhere between 1.6 and 2.2 g/kg. Going much higher rarely adds benefit for muscle, though it is generally safe for healthy kidneys.
Protein per meal, timing and staying safe
Aim for 25–40 g per meal
To make the most of each meal, aim for about 0.3 g/kg — roughly 25–40 g of protein — enough to cross the leucine threshold that maximises muscle protein synthesis. For an 80 kg person that is around 30–35 g per meal across 3–4 meals. Going far above ~40 g in one sitting adds little extra muscle-building benefit, so spread protein through the day rather than loading it all at dinner.
How much food is that?
As a rough guide, 25–40 g of protein is about 120–150 g of cooked chicken or fish, 3–4 eggs plus a serve of dairy, a large tub of Greek yoghurt, or a couple of scoops of tinned tuna or legumes with a protein source. Plant-based eaters can hit the same targets with tofu, tempeh, legumes, soy milk and a wider spread of foods.
Is high protein safe?
For people with healthy kidneys, higher protein intakes in the ranges above are considered safe. However, anyone with kidney disease should get medical advice before increasing protein, and protein needs during pregnancy differ — follow your doctor's or dietitian's advice. This tool is a general planning estimate, not a prescription.
❓ Frequently asked Frequently asked questions
How much protein do I need a day?
It depends on your goal and bodyweight. The RDA of 0.8 g per kilogram of bodyweight is the minimum to avoid deficiency — about 64 g for an 80 kg adult. Most active people do better higher: around 1.2–1.6 g/kg for general fitness, 1.6–2.2 g/kg to build muscle, and 1.8–2.4 g/kg when losing fat and trying to keep muscle. Multiply the g/kg figure by your weight in kilograms to get grams a day. This is general guidance, not medical advice.
How much protein to build muscle?
For building muscle, aim for roughly 1.6–2.2 g of protein per kilogram of bodyweight a day. For an 80 kg person that is about 128–176 g, so a common target is around 1.8 g/kg ≈ 144 g a day. Spread it across 3–5 meals of about 25–40 g each, and pair it with resistance training and enough total energy — protein alone won't build muscle without the training stimulus.
How much protein when losing weight?
When you are in a calorie deficit, higher protein helps preserve muscle and keeps you fuller. Aim for about 1.8–2.4 g/kg — roughly 144–192 g a day for an 80 kg person. If you are carrying more body fat, basing the figure on a target or lean bodyweight avoids over-estimating. Combine it with resistance training so the weight you lose is fat rather than muscle.
Is the 0.8 g/kg RDA enough?
The 0.8 g/kg RDA is set as the minimum to prevent deficiency in a sedentary adult, not the amount that is optimal. If you exercise, are building or keeping muscle, are dieting, or are over about 50, most evidence points to eating more — commonly 1.2–2.2 g/kg. So 0.8 g/kg is "enough" to avoid a shortfall, but usually below what best supports training and healthy ageing.
How much protein per meal?
To make the most of each meal for muscle, aim for about 0.3 g of protein per kilogram of bodyweight — roughly 25–40 g for most adults — enough to cross the "leucine threshold" that switches on muscle protein synthesis. For an 80 kg person that is around 30–35 g per meal across 3–4 meals. Going far above ~40 g in one sitting adds little extra muscle-building benefit, so spreading protein through the day beats one big hit.
Where these figures come from
The method here reflects mainstream sports-nutrition guidance, not a country-specific rule. The grams-per-kilogram ranges and the per-meal figure are common planning numbers; individual needs vary widely, so treat every number as a starting point.
- RDA baseline — 0.8 g of protein per kilogram of bodyweight a day, the minimum to prevent deficiency in a sedentary adult.
- Active and muscle-building ranges — commonly 1.2–1.6 g/kg for general fitness, 1.6–2.2 g/kg to build muscle, and 1.8–2.4 g/kg when dieting to preserve muscle.
- Per meal — about 0.3 g/kg (roughly 25–40 g) to maximise muscle protein synthesis via the leucine threshold, spread across 3–5 meals.
- Older adults — higher intakes help counter age-related muscle loss (sarcopenia).
Last checked: July 2026. This is a general planning estimate, not medical advice. Needs vary with body size, activity, goal and health. Anyone with kidney disease should get medical advice before raising protein, and protein needs in pregnancy differ — follow your doctor's or dietitian's advice.
Select the question that matches where you are right now.
The headline number is your estimated daily protein target in grams, based on your bodyweight and goal. The breakdown shows the g/kg figure used, your total grams a day, and how much protein to aim for in each meal.
Use it as a daily target to aim near, spread across your meals rather than all at once. Aim for about 25–40 g of protein per meal to make the most of each one.
It is not medical advice or a fixed prescription. It does not account for kidney disease, pregnancy or medical conditions. If you have kidney disease, get medical advice before raising protein.
Protein builds muscle only alongside resistance training and enough total energy. On its own, more protein won't add muscle or melt fat.
Three things move your daily protein target the most: your bodyweight, your goal, and how you split it across meals.
The target scales straight off your weight — the heavier you are, the more grams a day at the same g/kg figure.
Your goal sets the g/kg figure, from 0.8 g/kg at rest up to 2.2 g/kg to build muscle or 2.4 g/kg when dieting to keep muscle.
Splitting your total into 3–5 meals of about 25–40 g each helps you cross the per-meal threshold that maximises muscle protein synthesis.
A few simple habits make hitting your protein target easy without overthinking it.
Build each meal around a protein source — meat, fish, eggs, dairy, tofu or legumes — so you reach 25–40 g without trying too hard.
Even portions across the day beat one huge serve, since there is a ceiling on how much muscle-building each meal drives.
Pair your protein with resistance training. The training is the signal; protein just supplies the building blocks.
Protein is one piece of the picture. Explore the rest of your health numbers with these related calculators.