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Free online daily protein needs calculator

How much protein do you need per day? This calculator estimates your daily target from body weight, activity level, and whether your goal is maintaining weight, building muscle.

Units
Daily protein target
—–— g / day
Per meal (÷ 3)
— g
Rate
— g / kg
About this calculator

How to use

  1. Toggle Imperial or Metric for your preferred weight unit.
  2. Enter your body weight.
  3. Select your activity level — be honest about actual training frequency and intensity.
  4. Select your goal: maintain weight, gain muscle, or lose weight.
  5. Your daily protein range, per-meal target, and g/kg rate appear instantly.

The formula

Protein (g) = weight (kg) × g/kg rate

The g/kg rate is determined by goal and activity level:

Maintain:

Activityg/kg range
Sedentary0.8–1.0
Light1.0–1.2
Moderate1.2–1.4
Active1.4–1.6
Athlete1.6–1.8

Muscle gain ranges from 1.4–1.8 g/kg (sedentary) to 1.8–2.2 g/kg (active/athlete).

Weight loss ranges from 1.2–1.4 g/kg (sedentary) to 1.6–2.0 g/kg (athlete).

Per-meal values divide the daily total by 3.

Worked example

Person weighing 70 kg (154 lb), moderately active, goal: muscle gain:

Rate:        1.7–2.0 g/kg
Daily total: 70 × 1.7 = 119 g (min) | 70 × 2.0 = 140 g (max)
Per meal:    119 ÷ 3 ≈ 40 g | 140 ÷ 3 ≈ 47 g

Notes

  • Sources: Institute of Medicine DRI (RDA 0.8 g/kg); Academy of Nutrition and Dietetics Position Paper (2016); Morton RW et al. (2018) Br J Sports Med 52:376-384; Stokes T et al. (2018) Nutrients 10:180.
  • These are general targets for healthy adults. People with kidney disease should follow medical guidance on protein intake.

Frequently asked

How much protein do I need per day?
The RDA for sedentary adults is 0.8 g per kg of body weight — a floor, not an optimal target. For active people, the Academy of Nutrition and Dietetics recommends 1.2–1.7 g/kg. For muscle gain, research supports 1.6–2.2 g/kg (Morton et al., 2018). For weight loss with muscle preservation, 1.2–1.6 g/kg is effective (Stokes et al., 2018). This calculator applies these evidence-based ranges by goal and activity level.
Why does activity level affect protein needs?
Exercise — especially resistance training — breaks down muscle protein. More training volume means more muscle damage to repair, which increases the body's demand for amino acids. Sedentary people can meet needs at 0.8–1.0 g/kg; athletes in heavy training may need twice that to support recovery and adaptation.
Should I eat more protein when losing weight?
Yes. During a calorie deficit, higher protein intake helps preserve lean muscle mass that would otherwise be lost alongside fat. Research consistently shows that protein intakes of 1.2–1.6 g/kg support better muscle retention during weight loss compared to the minimum RDA.
Does protein timing across meals matter?
Muscle protein synthesis responds to each meal's leucine content. Most research suggests spreading protein across 3–4 meals of 20–40 g each maximizes daily synthesis — the body can only use roughly 20–40 g per sitting for muscle building. Eating 150 g in one meal does not provide the same stimulus as 50 g × 3. The per-meal values in this calculator assume three equal meals.
Can I share my results with a link?
Yes. Use the "Share with my numbers" button to copy a URL with your weight, activity level, and goal encoded as query parameters. Anyone who opens it sees the same inputs pre-filled.