Protein Calculator

Find how much protein to eat per day in grams, based on your body weight and goal — from the RDA baseline to muscle-building and fat-loss ranges.

Goal / activity
  • Sedentary — RDA baseline
  • General fitness / active
  • Build muscle / strength
  • Losing fat (preserve muscle)
  • Endurance training
Recommended protein —g/day
Enter your weight
Suggested daily range—
Grams per kg of bodyweight—
Per meal (4 meals/day)—

Ranges follow the RDA (0.8 g/kg) and ISSN/ACSM athlete guidance (~1.2–2.2 g/kg).

Protein is the nutrient your body uses to build and repair muscle, skin, enzymes, and hormones. How much you need depends mostly on your body weight and how active you are. This calculator turns those into a daily target in grams.

How much protein per day?

Guidelines are expressed as grams of protein per kilogram of body weight:

Goal / activityProtein (g/kg)
Sedentary (RDA baseline)0.8–1.0
General fitness / active1.2–1.6
Endurance training1.2–1.4
Building muscle / strength1.6–2.2
Losing fat (preserve muscle)1.6–2.4

The 0.8 g/kg figure is the Recommended Dietary Allowance — the minimum to avoid deficiency in a sedentary adult. Most people who exercise, and anyone trying to change their body composition, do better toward the higher ranges, which are supported by the International Society of Sports Nutrition.

Worked example

For a 70 kg person aiming to build muscle (1.6–2.2 g/kg):

  • Low end: 70 × 1.6 = 112 g/day
  • High end: 70 × 2.2 = 154 g/day
  • Midpoint target: about 133 g/day, or roughly 33 g across four meals

Getting it consistently

Hitting your protein target reliably matters more than the exact number. Anchor each meal around a protein source (eggs, dairy, meat, fish, legumes, tofu, or a protein supplement), aim for a similar amount at each, and you’ll land near your daily total without having to track every gram.

Frequently asked questions

How much protein do I need per day?

The RDA to prevent deficiency is 0.8 g per kg of body weight — about 56 g for a 70 kg adult. Active people, and anyone building muscle or losing fat, generally do better on 1.2–2.2 g/kg. This calculator shows the range for your weight and goal.

Is more protein always better?

Up to a point. Benefits for muscle and appetite level off for most people around 1.6–2.2 g/kg; eating well above that rarely adds more. Very high intakes are safe for healthy kidneys but simply displace other foods.

Should I spread protein across the day?

Yes — muscle protein synthesis responds best to roughly 20–40 g of protein per meal, so splitting your total across 3–4 meals is more effective than one large serving. This tool shows a per-meal figure to make that easier.

Do I use body weight or lean mass?

This calculator uses total body weight, which is how the common g/kg guidelines are defined. If you carry a lot of excess fat, basing protein on a target or lean body weight can be more appropriate — ask a dietitian if unsure.

References