Your basal metabolic rate (BMR) is the energy you use at complete rest – for breathing, your heartbeat and keeping warm. You work it out with the Mifflin-St Jeor equation from your weight, height, age and sex. A woman aged 35, 168 cm tall and weighing 68 kg comes to about 1,394 kcal a day.
Your basal metabolic rate (BMR) is the energy you use at complete rest – for breathing, your heartbeat and keeping warm. You work it out with the Mifflin-St Jeor equation from your weight, height, age and sex. A woman aged 35, 168 cm tall and weighing 68 kg comes to about 1,394 kcal a day.
Example:
1,394 kcal a day
With everyday life and exercise (what you burn in a day):
Your BMR is not an eating target: what you need in a day is your total expenditure below.
Worked out: 10 × 68 + 6.25 × 168 − 5 × 35 − 161 = 1,394 kcal
An estimate: the real value can differ by 10% or more.
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At 30, in kcal a day. Every 10 years older it is 50 kcal less.
| Height | 55 kg | 65 kg | 75 kg | 85 kg | 95 kg |
|---|---|---|---|---|---|
| 155 cm | 1,208 | 1,308 | 1,408 | 1,508 | 1,608 |
| 160 cm | 1,239 | 1,339 | 1,439 | 1,539 | 1,639 |
| 165 cm | 1,270 | 1,370 | 1,470 | 1,570 | 1,670 |
| 170 cm | 1,302 | 1,402 | 1,502 | 1,602 | 1,702 |
| 175 cm | 1,333 | 1,433 | 1,533 | 1,633 | 1,733 |
| 180 cm | 1,364 | 1,464 | 1,564 | 1,664 | 1,764 |
| Height | 65 kg | 75 kg | 85 kg | 95 kg | 105 kg |
|---|---|---|---|---|---|
| 165 cm | 1,536 | 1,636 | 1,736 | 1,836 | 1,936 |
| 170 cm | 1,568 | 1,668 | 1,768 | 1,868 | 1,968 |
| 175 cm | 1,599 | 1,699 | 1,799 | 1,899 | 1,999 |
| 180 cm | 1,630 | 1,730 | 1,830 | 1,930 | 2,030 |
| 185 cm | 1,661 | 1,761 | 1,861 | 1,961 | 2,061 |
| 190 cm | 1,693 | 1,793 | 1,893 | 1,993 | 2,093 |
Source: American Journal of Clinical Nutrition, 1990
| Age | Woman, 168 cm, 68 kg | Man, 180 cm, 80 kg |
|---|---|---|
| 20 years | 1,469 kcal | 1,830 kcal |
| 30 years | 1,419 kcal | 1,780 kcal |
| 40 years | 1,369 kcal | 1,730 kcal |
| 50 years | 1,319 kcal | 1,680 kcal |
| 60 years | 1,269 kcal | 1,630 kcal |
| 70 years | 1,219 kcal | 1,580 kcal |
BMR × factor. The last column is the woman from the example (BMR 1,394 kcal).
| Level | Factor | For example | A day |
|---|---|---|---|
| Hardly active | 1.2 | Sitting at work and at home, hardly any walking | 1,673 kcal |
| Lightly active | 1.375 | Office job plus exercise 1–3× a week, or lots of walking | 1,917 kcal |
| Active | 1.55 | On your feet a lot or exercise 3–5× a week | 2,161 kcal |
| Very active | 1.725 | Physical work or exercise almost every day | 2,405 kcal |
Example: Woman, 35 years, 168 cm, 68 kg:
With the Mifflin-St Jeor equation: 10 × weight in kg + 6.25 × height in cm − 5 × age in years, then +5 for men or −161 for women. For a woman aged 35, 168 cm and 68 kg: 10 × 68 + 6.25 × 168 − 5 × 35 − 161 = 1,394 kcal.
In the Mifflin-St Jeor equation, every year of age counts 5 kcal less – so 10 years is 50 kcal. The “BMR by age” table shows this for two examples.
Almost. BMR is measured under strict conditions: in the morning after about 8 hours of sleep, around 12 hours after your last meal, at rest. Resting metabolic rate (RMR) is about 10% higher, according to the DGE. The Mifflin-St Jeor equation was developed on resting energy expenditure; the app and most calculators call the result BMR.
In a comparison of the common equations, Mifflin-St Jeor was most often within 10% of the measured value in healthy adults, more often than Harris-Benedict (Frankenfield 2005). That’s why this calculator and the app use Mifflin-St Jeor.
It depends on height, weight and age. At 30: a woman of 165 cm and 65 kg about 1,370 kcal; a man of 180 cm and 85 kg about 1,830 kcal. The table above shows more.
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