Protein Calculator

Estimate your daily protein needs in grams based on weight, activity, and goal. Free protein intake calculator with TDEE and macro split.

A protein calculator estimates how many grams of protein you should eat each day based on your body weight and activity level. Protein rebuilds muscle, supports recovery, and during a calorie deficit it is the macro that protects lean mass. The Recommended Dietary Allowance starts at 0.8 g per kilogram for sedentary adults, but people who train or are in a cut need more — typically 1.6 to 2.2 g per kilogram — to maximize muscle retention and growth. This calculator layers a per-kilogram protein target onto your total daily energy expenditure so the protein number fits your actual calorie budget. Use it to set a daily protein target, to compare sedentary versus training needs, or to see how protein scales when you gain or lose weight. Enter your weight, height, age, and activity level; the goal field sets the per-kilogram factor — 0.8 g/kg for maintenance, 1.2 g/kg for weight loss, 1.8 g/kg for muscle gain, 2.2 g/kg for heavy training. Everything runs locally in your browser.

body

activity

Result

144 g

Breakdown

Protein per kg
1.8 g/kg
TDEE (kcal)
2,740
Calories from protein
576
Protein as % of TDEE
21 %

About Protein Calculator

What is protein calculator?

A protein calculator estimates how many grams of protein you should eat each day based on your body weight and activity level. Protein rebuilds muscle, supports recovery, and during a calorie deficit it is the macro that protects lean mass. The Recommended Dietary Allowance starts at 0.8 g per kilogram for sedentary adults, but people who train or are in a cut need more — typically 1.6 to 2.2 g per kilogram — to maximize muscle retention and growth. This calculator layers a per-kilogram protein target onto your total daily energy expenditure so the protein number fits your actual calorie budget. Use it to set a daily protein target, to compare sedentary versus training needs, or to see how protein scales when you gain or lose weight. Enter your weight, height, age, and activity level; the goal field sets the per-kilogram factor — 0.8 g/kg for maintenance, 1.2 g/kg for weight loss, 1.8 g/kg for muscle gain, 2.2 g/kg for heavy training. Everything runs locally in your browser.

How to use this calculator

  1. Enter your weight.
  2. Enter your height.
  3. Enter your age.
  4. Enter your sex.
  5. Enter your activity level.
  6. Enter your goal.
  7. Click the "Calculate" button.
  8. View your result instantly — the main result is displayed prominently at the top with a detailed breakdown below it.

When to use this calculator

  • Setting a daily protein target for muscle gain or retention
  • Comparing sedentary 0.8 g/kg versus training 1.8 g/kg needs
  • Protecting lean mass during a calorie cut
  • Estimating total daily energy expenditure before splitting macros
  • Checking how a higher activity level raises both calories and protein

How the calculation works

The calculator estimates basal metabolic rate with Mifflin-St Jeor (BMR = 10 x weight_kg + 6.25 x height_cm - 5 x age + sex, where sex is 5 for males and -161 for females), then TDEE = BMR x activity multiplier. A per-kilogram protein factor (about 1.8 g/kg for training, 0.8 g/kg for sedentary) multiplied by body weight gives the daily protein target in grams, and that target is scaled within your TDEE calorie budget. For example, a 30-year-old man at 80 kg, 178 cm, moderately active: BMR = 10 x 80 + 6.25 x 178 - 5 x 30 + 5 = 800 + 1112.5 - 150 + 5 = 1767.5, TDEE = 1767.5 x 1.55 ~= 2,740 kcal. At 1.8 g/kg his protein target is about 144 g/day, contributing roughly 576 kcal (144 x 4) — about 21% of his calorie budget.

Frequently Asked Questions

How much protein do I need per day?▼
The Recommended Dietary Allowance starts at 0.8 g per kilogram for sedentary adults. People who train or are in a calorie deficit typically need 1.6 to 2.2 g per kilogram to maximize muscle retention and growth.
Is 0.8 g/kg of protein enough?▼
0.8 g/kg is the minimum to prevent deficiency in sedentary adults, not an optimal target. If you lift weights, do endurance training, or are losing weight, aim higher — usually 1.6 to 2.2 g/kg.
How much protein for muscle gain?▼
For muscle gain, about 1.6 to 2.2 g per kilogram of body weight per day is the evidence-based range. Above 2.2 g/kg the extra protein shows diminishing returns for muscle building.
Should protein be higher when cutting?▼
Yes. In a calorie deficit, a higher protein intake (around 2.0 to 2.2 g/kg) helps preserve lean muscle mass while you lose fat. Protein is also more satiating than carbs or fat.
How is the protein target calculated here?▼
The calculator finds your TDEE with Mifflin-St Jeor, then applies a per-kilogram protein factor based on your goal (about 0.8 g/kg for maintain, 1.2 g/kg for loss, 1.8 g/kg for muscle gain) multiplied by your body weight in kilograms.
Can you eat too much protein?▼
For healthy adults, up to about 2.0 to 2.2 g/kg is well-tolerated long-term. Very high intakes above 3 g/kg offer little benefit and can crowd out other nutrients. People with kidney disease should follow medical guidance.
Does protein count toward my calories?▼
Yes. Protein provides about 4 calories per gram. A 144 g daily target contributes about 576 kcal, which this calculator shows as a percentage of your TDEE.
Is this protein calculator free?▼
Yes, this protein calculator is free and runs entirely in your browser. Enter your weight, height, age, sex, activity level, and goal to get your daily protein target in grams.

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