Protein intake calculator
How many grams of protein should you actually eat per day? It depends on two things: your body weight and how active you are.
- Based on standard published formulas
- Instant, easy-to-read estimates
- Private: nothing leaves your device
Protein intake calculator
Enter your numbers and press Calculate
The formula: body weight times an activity factor
The math is straightforward:
daily protein (g) = body weight (kg) × factor (g/kg)
And if you spread it over four meals:
protein per meal (g) = daily protein (g) ÷ 4
The factor depends on how active you are. Common reference ranges from the sports nutrition literature are:
- Sedentary (desk job, little structured exercise): 0.8–1.0 g/kg
- Active (daily walking, recreational running or sports): 1.2–1.7 g/kg
- Strength training (lifting with the goal of building muscle): 1.6–2.2 g/kg
Worked example: someone who weighs 82 kg (about 180 lb) and lifts weights, using a factor of 1.6 g/kg, needs 82 × 1.6 = 131.2, which rounds to 131 g of protein per day. Split across four meals: 131.2 ÷ 4 = 32.8, which rounds to 33 g per meal. For scale, a 6 oz chicken breast has roughly 50 g and a cup of Greek yogurt about 20 g.
The calculator rounds both results to the nearest whole gram — nobody weighs their dinner to three decimal places.
Examples by activity level
Three typical profiles, with the numbers the calculator would return:
- Sedentary office worker, 75 kg (165 lb). Sits most of the day, no structured exercise. At 0.8 g/kg: 75 × 0.8 = 60 g per day, about 15 g per meal. A couple of eggs at breakfast and a turkey sandwich at lunch get most of the way there.
- Recreational runner, 68 kg (150 lb). Runs three or four times a week. At 1.4 g/kg: 68 × 1.4 = 95.2 → 95 g per day, roughly 24 g per meal. A chicken salad and a cup of cottage cheese cover two of those meals easily.
- Strength athlete, 90 kg (198 lb). Lifts four to five days a week trying to add muscle. At 2.2 g/kg: 90 × 2.2 = 198 g per day, about 50 g per meal. That takes planning: chicken breast, lean ground beef, eggs, Greek yogurt — and maybe a whey shake, since hitting 198 g from whole food alone is a part-time job (a $30 tub of whey buys you about 70 servings of 24 g each).
Notice how the target more than triples from sedentary to strength training — which is exactly why copying someone else's number rarely works.
How to use the calculator
1. Enter your weight in kilograms. If you think in pounds, divide by 2.2 first (180 lb ≈ 82 kg). Your bathroom scale reading is plenty accurate for this. 2. Pick the g/kg factor that matches your activity. When in doubt, start mid-range: 0.9 if you are sedentary, 1.4 if you move daily, 1.8 if you lift. Adults over 65 generally do better at the higher end of their range to help preserve muscle mass. 3. Read both results. The first number is your total daily target; the second is the share for each of four meals. If you eat three meals, just divide the daily total by three — the exact split matters far less than hitting the daily total. 4. Compare against what you actually eat. Track one normal day and add up the protein from nutrition labels. If you fall short, scale up cheap whole-food sources (eggs, beans, dairy, chicken) before reaching for supplements.
If you have kidney or liver disease or any diagnosed medical condition, the right factor for you may be very different. This tool is for educational purposes only and is not a substitute for advice from a physician or registered dietitian.
Frequently asked questions
How much protein do I need per day if I don't exercise?
For a sedentary adult, the standard reference is 0.8 to 1.0 grams per kilogram of body weight per day. Someone weighing 75 kg (165 lb) would land between 60 and 75 g daily. That is the floor needed to cover basic bodily functions; many researchers consider 1.0–1.2 g/kg a more sensible target, especially past age 50, to slow age-related muscle loss.
Is eating a lot of protein bad for your kidneys?
In healthy people, systematic reviews have not found kidney damage from intakes up to 2.2 g/kg sustained over time. The picture changes entirely if kidney disease is already present: protein is often restricted in that case, and the target should be set by a nephrologist or registered dietitian. If you have any doubts about your kidney health, check with your doctor first.
Do I have to split my protein across exactly four meals?
No. The calculator divides by four because it is a convenient split that supports muscle protein synthesis, but the daily total is what matters most. There is evidence that doses of 20-40 g per meal are somewhat more efficient for building muscle than cramming everything into one giant dinner, so if you lift, aim for a solid serving at each main meal. If you eat three meals, just divide the total by three and move on.
Does plant protein count the same as animal protein?
It counts toward the total, yes — with one nuance: plant sources (beans, tofu, seitan, nuts) tend to have less complete amino acid profiles and somewhat less leucine than animal sources. Combining sources throughout the day (rice and beans, hummus and whole wheat pita) largely eliminates the issue. If you eat fully plant-based, you can compensate by aiming at the top of your range — say 2.0 instead of 1.7 g/kg.
About this calculator
A desk job with the occasional weekend walk is a very different situation from lifting weights four times a week at the local gym. This calculator multiplies your weight in kilograms by a grams-per-kilogram factor (from 0.8 to 2.5 g/kg) and gives you a daily target, plus a per-meal amount if you split it across four meals. That way you can tell whether your usual chicken breast, Greek yogurt, and eggs already cover it, or whether you are falling short before you even consider dropping $30 on a tub of whey.