BMR calculator
The calories your body burns at rest, and on a normal day.
- Calories at rest
- Daily burn by activity
- Three formulas
- In Indian food
I’m a aged . I weigh and I’m tall, so at rest my body burns about
1,555 kcal
A day at rest · Mifflin-St Jeor
Your BMR as the years go by
Point at a column to read itTap a column to read it
Facts checked 18 Oct 2026Your numbers stay on your device
Please note. A BMR from a formula is an estimate: real needs can differ by about 10% either way, and more with illness, thyroid problems, medicines, pregnancy or breastfeeding. This is a guide, not medical advice; a doctor or dietitian can help with your own plan.
Facts checked 18 Oct 2026Your numbers stay on your device
Please note. A BMR from a formula is an estimate: real needs can differ by about 10% either way, and more with illness, thyroid problems, medicines, pregnancy or breastfeeding. This is a guide, not medical advice; a doctor or dietitian can help with your own plan.
What moves it most
1 of 3A 30-minute walk most days moves you from desk job to light: about +272 kcal a day.
Your BMR by three formulas
Each formula was built on a different group of people, so they never agree exactly. kcal a day.
- 1Harris-BenedictMostrevised 19841,595+40 kcal
- 2Mifflin-St JeorYours1990, the default1,555
- 3Katch-McArdlelean mass 48.8 kg1,423−132 kcal
Katch-McArdle ignores age and sex and uses only lean mass.
BMR calculator
The calories your body burns at rest, and on a normal day.
Your BMR 1,555 kcal
At 65 kg, 168 cm and 30 years, your body burns about 1,555 kcal a day at complete rest, and about 1,866 kcal on a desk job day.
- Daily burn, desk job
- 1,866 kcal
- On top of BMR
- +311 kcal
- Formula
- Mifflin-St Jeor
- Activity factor
- × 1.2
- BMR per kg
- 23.9 kcal
Guide
What BMR means
Your basal metabolic rate (BMR) is the energy your body uses in a day at complete rest: breathing, pumping blood, keeping warm, running the brain and repairing cells. It is the biggest part of what you burn in a day: about 80% for someone with a desk job, and nearer 55–65% for very active people. The rest goes on digesting food (about 10%) and on moving, from walking to the bus stop to a football match. BMR is the floor of your energy needs, which is why it is the starting point of every calorie plan.
Nobody measures BMR at home: it needs a lab, a fasting morning and a breathing hood. Formulas estimate it from your sex, age, weight and height, and for most healthy adults they land within about 10% of a measured value.
How to use this tool
- Pick your units: kg and cm, kg with feet and inches, or pounds.
- Choose man or woman, then type your age, weight and height. Decimals are fine.
- The answer is your BMR in kcal a day, with your daily burn for a desk job beside it.
- Turn on My activity if you walk, exercise or do physical work; Other formula to compare formulas; Calorie goal for a gentle target; In Indian food for a sense of scale.
The formulas, and why Mifflin-St Jeor is the default
| Formula | Men | Women |
|---|---|---|
| Mifflin-St Jeor (1990) | 10 × kg + 6.25 × cm − 5 × age + 5 | 10 × kg + 6.25 × cm − 5 × age − 161 |
| Harris-Benedict, revised (Roza and Shizgal, 1984) | 88.362 + 13.397 × kg + 4.799 × cm − 5.677 × age | 447.593 + 9.247 × kg + 3.098 × cm − 4.330 × age |
| Katch-McArdle | 370 + 21.6 × lean mass in kg | same |
The Academy of Nutrition and Dietetics evidence review (Frankenfield and colleagues, 2005) found Mifflin-St Jeor the most reliable of the common formulas for healthy adults, so it is the default here and in most clinics. Katch-McArdle uses lean mass (weight minus fat), so it suits people who know their body-fat percentage, especially very muscular people. Harris-Benedict usually reads a little higher.
A note for Indians: studies of Indian adults (British Journal of Nutrition, 1998, among others) found measured BMR often lower than formulas built on Western groups predict, for the same weight. Treat the number as a starting point and watch what your weight actually does over three or four weeks.
From BMR to daily burn
Multiply BMR by an activity factor:
| Activity | For example | Factor |
|---|---|---|
| Desk job | little exercise, scooter commute | 1.2 |
| Light | walks 1–3 days a week | 1.375 |
| Moderate | exercise 3–5 days a week | 1.55 |
| Active | hard exercise 6–7 days | 1.725 |
| Very active | physical job and training | 1.9 |
For a reference point, the ICMR-NIN Nutrient Requirements for Indians (2020) put the daily energy need of a sedentary 65 kg Indian man at about 2,110 kcal and of a sedentary 55 kg woman at about 1,660 kcal, as of October 2026. Your own number depends on your size and age.
Suresh, a bank clerk in Cuddalore
Suresh is 34, 170 cm and 72 kg. Mifflin-St Jeor gives a BMR of 1,618 kcal. With a desk job and his scooter, his daily burn is about 1,941 kcal. He starts a 30-minute evening walk along Silver Beach on most days, which moves him to light activity: about 2,224 kcal a day, about 280 kcal more, the same as a little under three rotis. With the walks, the gentle-loss target is about 1,724 kcal a day (500 under his burn) and checks his weight every Sunday morning.
BMR and age
Every formula except Katch-McArdle lowers BMR with age: Mifflin-St Jeor takes off 5 kcal for every year, so about 50 kcal a decade at the same weight. Much of the real fall comes from losing muscle, which is why strength work twice a week (squats, resistance bands, carrying shopping) is one of the best things for metabolism as you get older.
Common mistakes
- Eating at your BMR: BMR is what you burn lying still all day. Eating below it for long, without a doctor, is not advised.
- Counting exercise twice: if you pick an active level, don’t add your workout calories on top.
- Mixing units: typing feet into the centimetre box. Choose “kg · ft and in” if you know your height in feet.
- Trusting a scale’s body fat blindly: home scales can be off by 5% or more. Katch-McArdle is only as good as that number.
- Using it for children or in pregnancy: these formulas are for non-pregnant adults.
Sources
Facts checked 18 Oct 2026AJCNA new predictive equation for resting energy expenditure in healthy individuals (Mifflin, St Jeor et al.) · American Journal of Clinical Nutrition (PubMed)1990
The default BMR formula: 10 × kg + 6.25 × cm − 5 × age, plus 5 for men or minus 161 for women. Feb 1990
AJCNThe Harris Benedict equation reevaluated (Roza and Shizgal) · American Journal of Clinical Nutrition (PubMed)1984
The revised Harris-Benedict formula offered as the second formula. Jul 1984
JADAComparison of predictive equations for resting metabolic rate: a systematic review (Frankenfield et al.) · Journal of the American Dietetic Association (PubMed)2005
Why Mifflin-St Jeor is the default: the most reliable of the common formulas for healthy adults. May 2005
ICMRA brief note on Nutrient Requirements for Indians, the RDA and EAR (ICMR-NIN, 2020) · ICMR-National Institute of Nutrition2020
Reference daily energy needs: about 2,110 kcal for a sedentary 65 kg man and 1,660 kcal for a sedentary 55 kg woman. 2020
FAQs
What is a normal BMR?
Most adult women fall between about 1,100 and 1,500 kcal a day and most men between about 1,400 and 1,900. It depends mostly on your weight, height, age and how much muscle you carry.
Is BMR the same as the calories I should eat?
No. BMR is only what you burn at complete rest. To keep your weight, eat close to your daily burn, which is BMR times your activity factor, usually 20–60% more.
Which BMR formula is most accurate?
For healthy adults, Mifflin-St Jeor is the most reliable common formula. If you know your body-fat percentage, Katch-McArdle can suit muscular people better.
Can I increase my BMR?
Yes, a little: building muscle through strength training raises it, because muscle uses more energy than fat even at rest. Very low-calorie diets lower it.
Why is BMR lower for women?
On average women carry more fat and less muscle than men of the same weight, and fat uses less energy at rest. That is why the formulas differ by sex.
Does BMR go down with age?
Yes. Mifflin-St Jeor lowers it by 5 kcal for every year, about 50 kcal a decade, mainly because muscle tends to fall with age.
Is BMR different for Indians?
Studies have found measured BMR in Indian adults often a little lower than Western formulas predict for the same weight. Use the result as a starting point and adjust after a few weeks.