Protein Calculator
How much protein do you need? Enter your body weight and pick the group that fits you: a general healthy adult, an adult aged 65 or over, pregnancy, or regular exercise. The calculator gives a daily range in grams, grams per meal and, if you add calories, your protein share.
Protein calculator
How to use the protein calculator
- Enter your body weight. Use pounds or kilograms. If you are well above a healthy weight, ask a dietitian whether to base protein on a different weight.
- Pick your group. General adults use the 0.8 g/kg RDA, adults 65 and over 1.0 to 1.2, pregnancy 1.1, and regular exercisers 1.4 to 2.0 g/kg.
- Add calories if you know them. Optionally enter daily calories to see protein as a percentage and check it stays within the 10 to 35% guideline range.
- Spread it across the day. See the per-meal split for three or four meals. Eating protein at each meal is simpler than one large serving.
Not medical advice. This calculator gives general information from published formulas and is not a diagnosis, treatment or substitute for a doctor, midwife or registered dietitian. People with kidney disease, liver disease or other conditions, and anyone pregnant, should follow their care team before changing protein intake.
Protein targets by group
Protein (g/day) = body weight (kg) × grams per kg
Body weight in lb × 0.4536 = kg
| Group | Grams per kg per day | Source |
|---|---|---|
| General healthy adult | 0.8 | RDA, National Academies |
| Healthy adult 65 or over | 1.0–1.2 | PROT-AGE position paper |
| Pregnancy (2nd and 3rd trimester) | 1.1 | Dietary Reference Intakes |
| Regular exercise or strength training | 1.4–2.0 | ISSN position stand |
Worked examples
A 70 kg adult with no training. 70 × 0.8 = 56 g a day, about 19 g at each of three meals.
A 154 lb (70 kg) person lifting regularly. 70 × 1.4 to 2.0 = 98 to 140 g, which is 33 to 47 g per meal across three meals.
An 80 kg healthy adult aged 70. 80 × 1.0 to 1.2 = 80 to 96 g, about 20 to 24 g across four meals.
A calorie check. At 1,500 calories, 140 g of protein is 560 calories, or 37% of the day, above the 35% guideline ceiling, and the calculator warns you.
Reading the result
The RDA is set to prevent deficiency, not to optimise training, which is why exercisers are given a higher range. Higher intakes are a choice to discuss with your doctor if you have any kidney issue. For a full split of carbohydrate and fat use the macro calculator, estimate your calorie needs with the calorie calculator, and for strength training see the one-rep max calculator.
Practical tips
Aim for protein at each meal, choose a mix of plant and animal sources, and watch the sodium and saturated fat that come with some protein foods. If you are cutting calories with the weight loss calculator, keeping protein at the higher end of your range is a common way to hold on to muscle, though the evidence is strongest for people who also do resistance training.
Frequently asked questions
How much protein do I need per day?
The RDA for healthy adults is 0.8 grams per kilogram of body weight, which is 56 g for a 70 kg person. It is the amount that meets the needs of nearly all healthy adults who are not training hard.
How much protein if I lift weights or train?
The International Society of Sports Nutrition position stand recommends 1.4 to 2.0 g/kg a day for most exercising people, which is 98 to 140 g for a 70 kg person.
Do older adults need more protein?
The PROT-AGE expert group suggests 1.0 to 1.2 g/kg for healthy adults over 65 to help preserve muscle, and more for some with illness, under medical guidance.
How much protein in pregnancy?
The Dietary Reference Intake for pregnancy is 1.1 g/kg a day. Your midwife or doctor may adjust that, so use it as a guide only.
Can too much protein hurt me?
Healthy adults tolerate intakes above the RDA, and the Dietary Guidelines allow up to 35% of calories. People with kidney disease or other conditions can be harmed by high intakes and should ask their doctor first.
Does protein per meal matter?
Spreading protein across meals is a common, practical approach. The calculator shows grams for three or four meals, but total daily protein matters most.
What are good protein foods?
Beans, lentils, tofu, fish, poultry, eggs, dairy, nuts and lean meat all contribute. Check labels for grams per serving, since a chicken breast, a cup of lentils and a tub of yoghurt differ widely.
Related calculators
Macro Calculator
Daily calories and grams of carbs, protein and fat for your goal.
Calorie Calculator (BMR & TDEE)
BMR, TDEE and maintenance calories with the Mifflin-St Jeor equation.
One-Rep Max (1RM) Calculator
Estimate your 1RM from weight and reps, with percentage table.
Weight Loss Calculator (Calorie Deficit)
Daily calories, deficit and a realistic goal date for a weight goal.
Sources and references
- National Academies – Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids
- Jäger R et al. (2017) – ISSN position stand: protein and exercise, J Int Soc Sports Nutr
- Bauer J et al. (2013) – Optimal dietary protein intake in older people: PROT-AGE position paper, J Am Med Dir Assoc
- Dietary Guidelines for Americans – acceptable macronutrient distribution ranges and fibre
About this calculator
Written and maintained by Rashid Mehmood, founder of CalcTen. The formulas are unit-tested against hand-worked examples, and the content is reviewed whenever product sizes or guidance change. Last updated 14 November 2026. See our editorial policy.
This calculator gives general information and is not medical advice, diagnosis or treatment. Results are estimates based on population averages. Talk to a doctor or other qualified health professional about your own situation. Read the disclaimer.