BMR (Metabolic Baseline) Calculator
The resting energy floor that training nutrition builds on.
Resting metabolic rate via Mifflin–St Jeor — the energy floor for fueling training.
Result
About this calculator
Basal Metabolic Rate (BMR) is the calories your body burns at complete rest — the energy floor under all activity.
The formula
Mifflin–St Jeor: men BMR = 10·kg + 6.25·cm − 5·age + 5; women = 10·kg + 6.25·cm − 5·age − 161.
Frequently asked questions
Q: BMR vs RMR?
A: BMR is strict rest; RMR (resting) is slightly higher and what most trackers estimate. BMR is the floor.
Q: Why Mifflin–St Jeor?
A: It is more accurate than the older Harris–Benedict equation across modern body types.
Q: How do I use BMR?
A: Add activity to get TDEE, then set intake above (bulk) or below (cut) it.
How to read the result
Basal metabolic rate is the energy the body spends at complete rest to keep organs, temperature, and tissue maintenance running, and the Mifflin-St Jeor equation estimates it from weight, height, age, and sex. It is the floor of your energy budget rather than a target to eat down to, because intake sustained below it pushes the body to reduce the very tissue that keeps the rate up.
Two cautions matter during a training cycle. The estimate carries a margin of roughly ten percent in either direction for a healthy adult, so a difference of a hundred calories is not meaningful. The rate also falls as weight falls, which is why a deficit that produced steady progress early in a cycle stalls later even when intake has not changed. Recalculate after a meaningful change in weight instead of relying on a figure from months ago.