Calculating your basal metabolic rate is straightforward once you know the BMR formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the BMR Calculator.
What is BMR?
The BMR calculation tells you your basal metabolic rate from a few simple inputs. The figure you are solving for here is the basal metabolic rate, expressed in kcal/day.
The BMR formula
This calculation combines several inputs through a multi-step method rather than a single one-line formula. Enter the values below and the calculator resolves each step in order. The inputs it needs are:
- Gender — a number. Example: 1.
- Age — a value measured in years. Example: 30 years.
- Weight — a value measured in kg. Example: 70 kg.
- Height — a value measured in cm. Example: 175 cm.
How to calculate it step by step
- Write down the gender (for example, 1).
- Write down the age (for example, 30 years).
- Write down the weight (for example, 70 kg).
- Write down the height (for example, 175 cm).
- Apply the formula above to get your basal metabolic rate.
- Double-check the result with the BMR Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Gender | 1 |
| Age | 30 years |
| Weight | 70 kg |
| Height | 175 cm |
| Basal metabolic rate | 1,649 kcal/day |
With gender of 1, age of 30 years, weight of 70 kg and height of 175 cm, the basal metabolic rate works out to 1,649 kcal/day.
Example 2
With gender of 1, age of 60 years, weight of 70 kg and height of 175 cm, the basal metabolic rate works out to 1,499 kcal/day.
| Result | Value |
|---|---|
| Basal metabolic rate | 1,499 kcal/day |
Example 3
With gender of 1, age of 15 years, weight of 70 kg and height of 175 cm, the basal metabolic rate works out to 1,724 kcal/day.
| Result | Value |
|---|---|
| Basal metabolic rate | 1,724 kcal/day |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
- These figures are general estimates, not medical advice — check with a qualified professional before acting on them.
Prefer not to do the maths by hand? — the BMR Calculator does it instantly, for free, with the formula and a worked example built in.
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