Protein calculator
Enter your age, sex and weight for the reference amount of protein for a healthy adult, in grams a day.
Updated 21 October 2026. Sources named on the page.
Key factThe NHMRC reference amount of protein for healthy adults aged 19 to 70 is 0.84 g per kg for men and 0.75 g per kg for women, so an 80 kg man needs about 67 g a day.
- Uses the Australian and New Zealand reference amounts per kilogram of body weight
- Metric or imperial
- Nothing you type is saved or sent
Find your reference amount
Free, in your browser. Nothing you type is saved or sent.
Keep your results in the Daily Journal
Habits, food, mood and sleep in one private place, with progress charts and a daily research card. Free to start.
- Every claim names its study
- Alone, as a couple or with a group
- Private by default
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.
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 |
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
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?
This calculator shows the national reference amount only. If you train hard, ask an accredited practising dietitian what is right for you. More is not automatically better.
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.
Keep going
Tools that go with this page
Each one shows an example screen, what the paid apps charge and what the Daily Journal does today.
Calorie counter app
Weight loss journal
Meal plannerTrack your protein without the maths
Sign up free for the Daily Journal app: habits, food, mood and sleep in one private place. Free to start.