Basal Metabolic Rate (BMR)
The calories your body burns at rest. The Mifflin–St Jeor equation is the most accurate formula for most adults and the one VivMetric uses.
Data updated: 2026-08-20 (verified vs primary service regulations)
Formula
Mifflin–St Jeor: Men: 10·weight(kg) + 6.25·height(cm) − 5·age + 5 · Women: 10·weight(kg) + 6.25·height(cm) − 5·age − 161
Healthy range
Roughly 1,400–1,900 kcal/day for most adults, varying with size, sex, age, and muscle mass.
Military & first-responder angle
A basic nutrition input for service members in the ABCP or trying to meet body-composition standards — knowing your BMR anchors a realistic deficit (3–8 lbs/month is the Army standard).
Calculator
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.
Quick answers
Related metrics
WHtR
Waist circumference divided by height — the metric the U.S. military adopted as its joint-force body-compositi…
Read →Body fat %
The percentage of your weight that is fat. The U.S. Navy circumference method estimates it from height, neck, …
Read →BMI
Weight divided by height squared. Still used for general screening and in some enlistment height-weight tables…
Read →WHR
Waist divided by hip circumference — a classic central-obesity index that predates WHtR. The military uses WHt…
Read →TDEE
BMR multiplied by an activity factor — the calories you burn per day including training. The number to use whe…
Read →FFMI
Lean body mass relative to height — the metric that tells you whether you carry muscle or just weight, and whe…
Read →LBM
Your total weight minus fat — muscle, bone, organs, and water. Used to set protein targets and evaluate compos…
Read →Ideal weight
Devine, Robinson, Miller, and Hamwi formula estimates of a healthy weight for your height — planning reference…
Read →Water intake
Evidence-based hydration targets for your weight and activity — especially relevant to accurate weigh-ins and …
Read →