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BMR calculator (Mifflin–St Jeor)

  

Mifflin–St Jeor equation for adults.

Sex

years

Units

cm
kg

BMR

1,618 kcal

Calories a day at complete rest. Daily needs are higher: see TDEE.

Per hour
67 kcal
Sedentary day (× 1.2)
1,941 kcal

How we got this

  1. 10 × 70 kg = 700
  2. 6.25 × 170 cm = 1062.5
  3. 5 × 30 years = 150
  4. 700 + 1062.5 − 150 + 5 = 1617.5 kcal

What BMR tells you

BMR is the energy your organs use to keep you alive at rest. It is the floor, not a diet target. Eating below it for long periods is rarely a good idea without medical advice.

To turn it into a daily number, use the TDEE calculator. If you carry a lot of muscle, the equation will underestimate you; check body fat for a fuller picture.

Sources

What this calculator does not account for

  • Muscle mass: lean, muscular people burn more than the equation says.
  • Thyroid conditions, medication, pregnancy and illness.
  • Under-18s: the equation was built on adults.

How this is calculated

Formula: Mifflin–St Jeor

BMR =10 × kg + 6.25 × cm − 5 × age + 5 (men) or − 161 (women)

What the symbols mean

  • kgBody weight in kilograms.
  • cmHeight in centimetres.
  • ageAge in years.

Good to know

  • Imperial inputs are converted first: 1 lb = 0.4536 kg, 1 in = 2.54 cm.
  • Multiply BMR by an activity factor to get daily needs: the TDEE calculator does that.

Read the full methodologyFound an error? Contact us

Worked examples

Each example is worked out by the same code as the calculator above.

Man, 30, 175 cm, 70 kg

10 × 70 + 6.25 × 175 − 5 × 30 + 5 = 1648.75 kcal a day at rest.

Woman, 25, 165 cm, 60 kg

10 × 60 + 6.25 × 165 − 5 × 25 − 161 = 1345.25 kcal a day at rest.

Embed this calculator

The frame shows the tool only.

<iframe src="/embed/bmr" title="BMR calculator" width="100%" height="720" style="border:0;max-width:42rem" loading="lazy"></iframe>

Questions

What is a normal BMR?

Most adults fall between about 1,200 and 2,000 kcal a day. It rises with weight and height and falls with age.

Is BMR the same as the calories I should eat?

No. BMR is rest only. Daily needs add movement and digestion; that is TDEE, usually 1.2 to 1.9 times BMR.

Why Mifflin–St Jeor and not Harris–Benedict?

Studies comparing the two found Mifflin–St Jeor closer to measured values in modern adults, so dietitians use it most.