Protein calculator
Enter your age, sex and weight for the reference amount of protein for a healthy adult, in grams a day. Tick the box if you train regularly to see a higher figure too.
Updated 21 October 2026. Sources named on the page.
- Uses the Australian and New Zealand reference amounts per kilogram of body weight
- Metric or imperial
- An optional higher figure for people who train regularly
- Nothing you type is saved or sent
Find your reference amount
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The formula and the reference amounts
Protein in grams = grams per kilogram x your weight in kilograms. The reference amounts below are for healthy adults aged 19 and over; the optional higher figure is 1.6 g per kg.
Reference protein per kilogram of body weight, adults
| Age | Women (g per kg) | Men (g per kg) |
|---|---|---|
| 19 to 70 | 0.75 | 0.84 |
| 71 and over | 0.94 | 1.07 |
Worked examples
| Person | Working | Protein a day |
|---|---|---|
| Man, 40 y, 80 kg | 0.84 x 80 | 67.2 g |
| Woman, 40 y, 60 kg | 0.75 x 60 | 45 g |
| Man, 75 y, 80 kg | 1.07 x 80 | 85.6 g |
| Man, 40 y, 80 kg who trains (higher figure) | 1.6 x 80 | 128 g |
Sources: NHMRC and New Zealand Ministry of Health, Nutrient Reference Values for Australia and New Zealand (nrv.gov.au), recommended dietary intake of protein for adults; The 1.6 g per kg figure is a commonly used higher range for people who train; its source is to be cited before launch
Figures and sources checked 21 October 2026. General information, not medical advice.
Questions
How much protein do I need a day?
For healthy adults aged 19 to 70 the national reference amount is 0.75 grams per kilogram of body weight for women and 0.84 for men. Enter your weight above for your figure.
Do I need more protein if I exercise?
Some people who train regularly use a higher figure, commonly around 1.6 grams per kilogram. This calculator shows it if you tick the box. It is a starting point, not a requirement.
Is more protein always better?
No. The reference amount is enough for most healthy adults and more is not automatically better. If you have kidney disease or any medical condition, ask a doctor or accredited practising dietitian before changing your protein.
Does protein need change with age?
The reference amount is higher from age 71: 0.94 g per kg for women and 1.07 for men. The calculator applies it automatically.
Is this advice for pregnancy or children?
No. The calculator is for adults aged 19 and over and is not for pregnancy, breastfeeding or children. Talk to a doctor or accredited practising dietitian.
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