Basal metabolic rate calculator
Find out in seconds how many calories your body burns at rest (your basal metabolic rate, BMR) and how much you spend per day with your activity (your TDEE). We use the Mifflin-St Jeor formula, the most accurate per the evidence.
Your basal metabolism (BMR)
1699 kcal/day
Total expenditure (TDEE): 2633 kcal/day
What you burn per day with your activity — your maintenance calories.
Renzy computes your metabolism and target, and tracks your calories each day with a photo.
Basal metabolism estimated with the Mifflin-St Jeor formula (the most accurate per the evidence). Guidance, not medical advice.
What is basal metabolic rate and how is it calculated?
The basal metabolic rate (BMR) is the energy your body spends to stay alive at complete rest: breathing, pumping blood, keeping temperature, organ activity. It is 60-70% of your daily burn. We estimate it with the Mifflin-St Jeor formula using sex, age, height and weight: men, 10×weight + 6.25×height − 5×age + 5; women, the same but − 161. We then multiply that BMR by an activity factor to get your total daily energy expenditure (TDEE) — your maintenance calories.
FAQ
What is the difference between BMR and TDEE?
BMR is what you spend at complete rest; TDEE is what you spend per day including movement and exercise. TDEE is always higher — it is your BMR times an activity factor. For diets, TDEE is the number that matters.
Can you speed up basal metabolism?
Yes, modestly. Building muscle raises it, and eating enough protein while avoiding extreme diets helps not to slow it. Miracle tricks do not work; muscle and activity move the needle.
Why does my metabolism seem slower?
With age and after weight loss, BMR drops a bit. Genetics also play a role. If losing weight is hard, it is rarely a "broken" metabolism — usually you eat more than you think.
Is this formula accurate?
Mifflin-St Jeor is the most accurate popular one, but it is an estimate (±10%). Use it as a starting point and adjust by 100-200 kcal if your weight does not change as expected in 2-3 weeks.