BMR and daily calorie calculator
Your basal metabolic rate (BMR) is the energy your body uses at complete rest. Multiplying it by an activity factor gives a rough estimate of the calories you need each day.
How to use this calculator
- Choose sex and enter your age.
- Enter height in centimetres and weight in kilograms.
- Choose the activity level that matches your week.
- Read BMR and the maintenance calories, with rough figures for losing or gaining about half a kilo a week.
Worked examples
Example 1
A 30-year-old man, 170 cm, 70 kg, with light exercise.
You enter
| Sex | Male |
|---|---|
| Age (years) | 30 |
| Height (cm) | 170 |
| Weight (kg) | 70 |
| Activity level | Light exercise 1 to 3 days a week |
You get
| BMR (calories at complete rest) | 1,618 kcal a day |
|---|---|
| Maintenance calories | 2,224 kcal a day |
| About 0.5 kg a week lower | 1,724 kcal a day |
| About 0.5 kg a week higher | 2,724 kcal a day |
Example 2
A 35-year-old woman, 160 cm, 62 kg, with moderate exercise.
You enter
| Sex | Female |
|---|---|
| Age (years) | 35 |
| Height (cm) | 160 |
| Weight (kg) | 62 |
| Activity level | Moderate exercise 3 to 5 days a week |
You get
| BMR (calories at complete rest) | 1,284 kcal a day |
|---|---|
| Maintenance calories | 1,990 kcal a day |
| About 0.5 kg a week lower | 1,490 kcal a day |
| About 0.5 kg a week higher | 2,490 kcal a day |
How it works
The Mifflin-St Jeor equation is widely used for adults. The activity factor then scales the BMR to a typical day's total.
These numbers are estimates; people differ by several hundred calories. Use them as a starting point and adjust to your results. This is not medical advice, and anyone with a health condition should talk to a doctor or dietitian.
Formula
BMR = 10 x weight (kg) + 6.25 x height (cm) - 5 x age + 5 (men) or - 161 (women). Maintenance = BMR x activity factor.
Common questions
How many calories make a kilo of weight?
About 7,700 calories is the common rule of thumb, but real changes vary.
Is a 500-calorie deficit safe?
It is a common starting point for many adults, but not for everyone; ask a professional.
Which activity level should I choose?
Be honest and err lower.
Calculators give estimates for learning and planning. They are not financial, tax, legal or medical advice, and results depend entirely on the numbers you enter. Check rates, limits and rules with an official source or a qualified professional before acting.