Protein builds and repairs muscle and makes enzymes, hormones and antibodies. Needs rise with exercise, ageing, pregnancy and calorie restriction. Spreading 20–40 g across each meal maximises muscle building.
How to use the Protein Calculator
- Weight
- Goal and activity
- Meals per day
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter your weight and choose the description that fits you. Use goal or lean weight if you have a lot of weight to lose, to avoid overestimating.
Inputs explained
| Field | What to enter |
|---|---|
| Weight | Units: kg, lb, st, g |
| Goal and activity | Choose one: Sedentary adult (RDA 0.8 g/kg), Adult over 65 (1.1 g/kg), Active adult (1.2 g/kg), Pregnancy (1.1 g/kg) … |
| Meals per day | A number |
What each result means
- Daily protein = [Weight]×[Goal and activity]
- Per meal = [Daily protein]÷[Meals per day]
- Calories from protein = [Daily protein]×4
- RDA minimum (0.8 g/kg) = [Weight]×0.8
Example values
How the main result changes when Weight changes and everything else stays at the example values above:
| Weight (kg) | Daily protein (g/day) |
|---|---|
| 35 | 56 |
| 52.5 | 84 |
| 70 | 112 |
| 87.5 | 140 |
| 105 | 168 |
| 140 | 224 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
Protein (g/day) = weight (kg) × g per kg for your goal
RDA: 0.8 g/kg (adults), 1.0–1.2 g/kg (over 65)
AMDR: 10–35% of calories
Worked example
Inputs: Weight: 70 kg; Goal and activity: Strength training (1.6 g/kg); Meals per day: 4.
Results: Daily protein = 112 g/day; Per meal = 28 g; Calories from protein = 448 kcal; RDA minimum (0.8 g/kg) = 56 g/day.
Key terms
- RDA
- Recommended dietary allowance.
Frequently asked questions
Is too much protein harmful?
Up to about 2 g/kg is considered safe for healthy kidneys; people with kidney disease should ask their doctor.
Can I get enough protein on a plant-based diet?
Yes. Combine legumes, soy, grains, nuts and seeds through the day.
Do older adults need more protein?
Yes, about 1.0–1.2 g/kg to preserve muscle.
Sources
Guides on this topic
- How Many Calories Should I Eat? BMR, TDEE and Your Real Number: Your calorie target starts with BMR and TDEE, but the real number comes from adjusting after a few weeks. A step-by-step method with a full worked example.