Calculate BMR: Calculator Using Mifflin and Harris-Benedict
Updated: October 2026
In short: Basal metabolic rate is the energy your body uses at complete rest per day, usually around 1,200 to 1,500 kcal for an adult woman and around 1,500 to 1,900 kcal for a man. The calculator uses the Mifflin and St Jeor formula and shows the Harris-Benedict formula for comparison. As of: October 2026.
What is basal metabolic rate?
Basal metabolic rate (BMR) is the amount of energy your body needs at complete rest, lying down, fasted and at a neutral temperature to maintain breathing, heartbeat, body temperature and metabolism. For most adults it makes up the largest part of daily energy needs. How much more you use through daily life and exercise is shown by the calorie calculator.
How do you calculate BMR?
The calculator uses the Mifflin-St Jeor formula (1990), which is considered well suited for people with a normal or slightly elevated BMI. The Harris-Benedict formula (1919) is older and usually gives slightly higher values.
| Formula | Women | Men |
|---|---|---|
| Mifflin and St Jeor | 10 × kg + 6.25 × cm minus 5 × age minus 161 | 10 × kg + 6.25 × cm minus 5 × age + 5 |
| Harris and Benedict (original) | 9.5634 × kg + 1.8496 × cm minus 4.6756 × age + 655.1 | 13.7516 × kg + 5.0033 × cm minus 6.755 × age + 66.47 |
Worked example (Mifflin): woman, 35 years, 70 kg, 172 cm: 10 × 70 + 6.25 × 172 minus 5 × 35 minus 161 = 700 + 1,075 minus 175 minus 161 = 1,439 kcal.
Why do BMR and calorie needs differ?
BMR is only the basis. You get total energy expenditure by multiplying it by the activity factor (PAL), as the list in the result shows. Anyone who wants to lose weight shouldn't fall below their BMR on a lasting basis. You can read more in our article Calorie needs for weight loss; you can check your BMI with the BMI calculator.
How much energy does a juice cleanse provide in comparison?
For context: according to the product page, the frank. Juice Cleanse provides roughly 680 to 934 kcal per cleanse day depending on the variant (Pro to Starter), which is usually below your BMR. That is why it is meant as a short break and not as a permanent solution. You'll find the exact figures in the Juice Cleanse calorie calculator.
Frequently asked questions
What is a woman's BMR?
For adult women it is usually around 1,200 to 1,500 kcal per day, depending on age, height and weight. The calculator above gives you a personal estimate.
What is a man's BMR?
For adult men it is usually around 1,500 to 1,900 kcal per day, because on average they have more muscle mass.
Which formula is more accurate, Mifflin or Harris-Benedict?
Both are estimates. The Mifflin-St Jeor formula is newer and is often preferred for normal-weight to slightly overweight adults. The deviation from the actual value is often ten percent or more for both.
How can I increase my BMR?
Muscle mass uses more energy than fat tissue. Strength training and enough protein help maintain your BMR. Radical diets are more likely to lower it.
Does the calculator apply to children and pregnant women?
No. It is meant for healthy adults aged 18 to 100. Different values apply to children, pregnant and breastfeeding women.
Sources
Note: This content provides guide values for healthy adults and does not replace medical advice. If you have pre-existing conditions, are pregnant or breastfeeding, have an eating disorder or take medication, please talk to your doctor first.
