What is BMR?
Basal metabolic rate (BMR) is the energy needed at rest for breathing, circulation, temperature control and cell repair. It typically makes up 60–70% of daily energy use. Resting metabolic rate (RMR) is a close cousin measured under slightly less strict conditions. For most people the two differ by only a few percent.
Calculate your BMR
Enter your details in the calculator. The "Resting (BMR)" tile shows your result, and you can switch between Calories and kilojoules. The tool uses the Mifflin-St Jeor equation by default.
Example BMR values
These illustrative adults show how age and sex change resting energy. They are not Australian averages.
| Person | Height / weight | BMR (Cal) | BMR (kJ) |
|---|---|---|---|
| Woman, 25 | 165 cm / 65 kg | 1,400 | 5,858 |
| Woman, 40 | 165 cm / 65 kg | 1,320 | 5,523 |
| Woman, 60 | 165 cm / 65 kg | 1,220 | 5,104 |
| Man, 25 | 178 cm / 80 kg | 1,790 | 7,489 |
| Man, 40 | 178 cm / 80 kg | 1,720 | 7,196 |
| Man, 60 | 178 cm / 80 kg | 1,620 | 6,778 |
What affects BMR?
- Body size and composition: more lean mass means a higher BMR.
- Age: BMR drifts down roughly 1–2% per decade in adulthood, largely through loss of muscle.
- Sex: men on average have more lean mass than women of the same weight.
- Hormones and health: thyroid conditions and some medications can change BMR. See your GP if you suspect a problem.
BMR vs TDEE
BMR is not how much you should eat. Add movement, exercise and the energy used digesting food and you get TDEE, your maintenance calories. See how it works for the formulas.
Can you boost your BMR?
Not dramatically. Building muscle through resistance training raises it modestly over time, and keeping a very low intake for long periods can lower it. Be wary of "metabolism booster" claims.