Fitness calculator
Protein Intake Calculator
Plan a protein target using a rate appropriate to your weight unit and goals.
Use matching units (for example, kilograms with g/kg). Typical targets vary; this is a planning estimate, not medical advice.
Daily protein
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The two inputs, and what the tool doesn't do for you
Body weight and a "protein target" rate (grams per unit of body weight) are the only two fields, and the calculator simply multiplies them together — it has no unit dropdown and does no conversion between kilograms and pounds. If you weigh yourself in kilograms, the rate you enter has to be a grams-per-kilogram figure; if you weigh yourself in pounds, it has to be grams-per-pound. Mixing the two silently produces a number that looks plausible but is off by roughly a factor of 2.2.
Body weight must be greater than zero, but the rate field accepts zero, since "0 g per unit weight" is a mathematically valid, if pointless, input. Weekly total is simply the daily figure multiplied by seven — there's no averaging or day-to-day variation built in.
The protein target formulas
A 70 kg person using a 1.6 g/kg rate gets 70 × 1.6 = 112 g of protein per day, and 112 × 7 = 784 g per week. A heavier lifter at 82 kg using a higher 2.2 g/kg rate gets 82 × 2.2 = 180.4 g/day, 1,262.8 g/week.
In pounds, a 160 lb person using 0.7 g/lb gets 160 × 0.7 = 112 g/day — coincidentally the same daily number as the first example, since 0.7 g/lb works out to roughly 1.54 g/kg, a different rate than the 1.6 g/kg used above but close enough to land near the same total.
What a reasonable rate actually is — ranges, not a prescription
The RDA of 0.8 g/kg body weight per day is a minimum meant to prevent deficiency in a sedentary adult, not a target for someone doing regular resistance training. Sports-nutrition research on resistance-trained adults more commonly points to a range of roughly 1.6–2.2 g/kg per day for building or maintaining muscle, and some studies on lean, trained individuals eating in a calorie deficit — where the goal is preserving muscle while losing fat — have found benefits up to around 2.3–3.1 g/kg, though most people training for general fitness don't need to reach that upper end.
These figures come from published sports-nutrition research, not an individualized medical or dietary assessment, and the number this calculator produces is a planning estimate, not medical or nutrition advice. Anyone with kidney disease, another metabolic condition, or specific dietary needs should get a target from a registered dietitian or physician rather than from a rate picked off a general range.
Sample daily and weekly targets
Different goals call for different rates, all run through the same multiplication:
- Sedentary adult at the RDA minimum: 82 kg × 0.8 g/kg = 65.6 g/day, 459.2 g/week
- Muscle-building phase: 90 kg × 2.0 g/kg = 180 g/day, 1,260 g/week
- Preserving muscle during a calorie deficit: 68 kg × 2.6 g/kg = 176.8 g/day, 1,237.6 g/week
- Endurance training, moderate target: 65 kg × 1.4 g/kg = 91 g/day, 637 g/week
- Older adult using a higher-than-RDA rate to offset anabolic resistance: 70 kg × 1.1 g/kg = 77 g/day, 539 g/week
- Working in pounds: 140 lb × 0.8 g/lb = 112 g/day, 784 g/week
Frequently asked questions
Does the calculator convert between pounds and kilograms?
No. It multiplies exactly the two numbers you type in, so the rate you choose has to already match the unit you used for body weight — a g/kg rate with a kilogram weight, or a g/lb rate with a pound weight.
Why is a protein rate of 0 accepted but a body weight of 0 isn't?
A 0 g/kg rate is a valid, if trivial, input that produces a 0 g target. A body weight of 0 can't be multiplied into a meaningful protein number, so that field requires a value greater than zero.
What rate should I actually use?
The RDA minimum is 0.8 g/kg; sports-nutrition sources commonly cite 1.6–2.2 g/kg for people doing regular resistance training, with some research on lean, trained individuals in a calorie deficit going as high as 2.3–3.1 g/kg. These are ranges from published research, not a personal prescription.
How is the weekly figure calculated?
It's the daily total multiplied by seven, with no adjustment for training versus rest days. A 112 g/day target becomes a flat 784 g/week.
Can I use this for a percent-of-calories protein target instead of g per body weight?
Not directly — convert it first. Protein has about 4 kcal per gram, so a 2,000-calorie diet at 25% protein is (2,000 × 0.25) ÷ 4 = 125 g/day; divide that by your body weight to get an equivalent g/kg or g/lb rate to enter here.
Is this medical or nutrition advice?
No. The output is a planning estimate based on a rate you chose, not an individualized recommendation — talk to a registered dietitian or physician for a target that accounts for your health history.
This calculator is for informational and educational purposes only and is not medical advice. Its results are general estimates, not an individual assessment. Talk to a doctor, registered dietitian, or other qualified health professional before making decisions about your health, diet, or exercise.