Find BMR for women — the calories your body burns while resting.
The Mifflin-St Jeor equation, using the female-specific constant (−161).
Women: 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
A woman's basal metabolic rate is the energy her body spends in a day at complete rest. This calculator estimates it with the Mifflin-St Jeor equation using the female constant of −161, from weight, height and age.
Women commonly look up BMR when they want to lose weight gradually, regain energy after an illness, or plan meals for a new fitness routine. The number answers a narrow question: how many kilocalories would my body use if I did nothing all day? Real daily needs are higher, and the usual next step is to multiply BMR by an activity factor.
The formula applies to adult women who are not pregnant or breastfeeding. During pregnancy and lactation energy needs rise and follow separate guidance, so the result here should not be used then.
1. Write down weight in kg, height in cm and age in completed years.
2. Compute 10 × weight.
3. Compute 6.25 × height.
4. Compute 5 × age.
5. Apply the women's formula: BMR = 10 × weight + 6.25 × height − 5 × age − 161.
6. Multiply the result by an activity factor between 1.2 (mostly sitting) and 1.9 (very heavy daily training) to estimate total daily energy use.
The Mifflin-St Jeor study measured resting energy use in both men and women and fitted a single equation with a sex term. The weight, height and age coefficients are shared. Only the constant differs: +5 for men, −161 for women, a gap of 166 kcal a day. This reflects the average difference in fat-free mass, since muscle and organs use more energy than fat. At the same weight and height, women on average carry a higher share of body fat, so the formula predicts lower resting use. The correction is an average and will not fit every woman.
The −5 × age term means the estimate drops by 50 kcal a day for every ten years, all else equal. Part of this is a real fall in fat-free mass with age, which begins in adulthood and speeds up after menopause for many women. Strength training can slow that loss, so an active 50-year-old woman may measure above the formula. Weight changes also move BMR: losing 5 kg lowers the estimate by 50 kcal, which is one reason weight loss slows over time on a fixed diet.
Validation studies found Mifflin-St Jeor predicts measured resting energy within about 10% for a majority of adults, which is good for a formula with three inputs. Errors are larger at the extremes of body size and in conditions that change metabolism, such as thyroid disorders or polycystic ovary syndrome. If a carefully followed diet produces results very different from what the estimate predicts over several weeks, a doctor or dietitian can assess the reason and, where available, arrange indirect calorimetry for a measured value.
Meena is a 45-year-old school principal in Coimbatore who weighs 58 kg and is 155 cm tall. She wants to know her resting calorie needs before joining a yoga class.
Answer: BMR 1,163 kcal/day
Eating only BMR calories for weeks, which is usually too little once daily movement is counted.
Using the result during pregnancy or breastfeeding, when energy needs are higher and follow different guidance.
Assuming the figure stays fixed after weight loss; recalculate after every few kilograms.
Choosing the men's formula or a unisex average, which overstates a woman's estimate by up to 166 kcal.
Taking a single slow month of weight loss as proof the formula is wrong; water and hormonal changes can mask fat loss for a while.
Setting a starting calorie budget for gradual weight loss.
Planning meals after joining yoga, dance or gym classes.
Showing how resting needs change with age when reviewing a long-term diet.
Dietitians preparing a first estimate before a detailed assessment.
Does this account for pregnancy or breastfeeding?
No. This is the standard formula for an adult who is not pregnant or breastfeeding. Energy needs are higher during pregnancy and breastfeeding, and need separate guidance.