BMR Calculator (Basal Metabolic Rate)
Enter weight, height, age, and sex on the left; the BMR result updates instantly on the right, with daily energy by activity level below.
Input
The result updates automatically as you type.
Result
- Weight term (10×kg)
- —
- Height term (6.25×cm)
- —
- Age term (−5×yr)
- —
- Sex adjustment
- —
Daily energy by activity level
Daily energy = BMR × activity factor (1.2–1.9), in kcal/day. Each point is one activity level.
This estimate uses the Mifflin-St Jeor equation and is not medical advice. Pregnancy, medical conditions, or high muscle mass can shift your real metabolic rate.
ready to use.
- Visible firstKeep the input and result positions clear.
- Results firstPut the main number up front and keep the process secondary.
- Less to askNo sign-up or extra information before using the tool.
How to read BMR as a planning number
Basal metabolic rate (BMR) is the minimum energy your body spends per day while awake but completely at rest. It covers breathing, temperature regulation, and organ function, so it forms the largest share of total daily calories.
The numbers on this page are estimates from the Mifflin-St Jeor equation. Muscle mass, hormones, and health conditions can move your real rate, so treat the result as a starting point for diet and training plans.
The Mifflin-St Jeor equation adds four terms
This calculator uses the equation published in 1990 by Mifflin and St Jeor. Weight and height increase the result, age decreases it, and a sex adjustment is added at the end.
- Weight term = 10 × weight (kg)
- Height term = 6.25 × height (cm)
- Age term = −5 × age
- Sex adjustment = +5 for men, −161 for women
Screen flow: input, result, activity
Change any value in the left panel and the right panel recalculates without a calculate button. The four term cards under the main number show what pushed the result up or down, and the activity table extends it to daily energy.
Switching between lb·ft/in and kg·cm
Changing the unit selector converts the values you already entered. The math always runs in metric internally, so both unit systems give the same baseline.
- 1 lb = 0.45359237 kg
- 1 in = 2.54 cm
- Feet and inches are combined into total inches, then converted to cm
Activity factors from 1.2 to 1.9
Multiplying BMR by an activity factor approximates total daily energy expenditure (TDEE). The five levels are conventional bands; real activity varies from person to person.
- Sedentary ×1.2
- Lightly active ×1.375
- Moderately active ×1.55
- Very active ×1.725
- Extremely active ×1.9
Male example: 160 lb · 5'9" · age 30
The default profile on the English page. Converted to metric (about 72.6 kg, 175.3 cm), the four terms add to roughly 1,676 kcal per day at rest.
- Weight term
- 10 × 72.6 = +726
- Height term
- 6.25 × 175.3 = +1,095
- Age term
- −5 × 30 = −150
- Sex adjustment
- Male +5 → about 1,676 kcal/day
Female example: 130 lb · 5'4" · age 28
The sample button applies this profile. Because the female adjustment is −161, the result is lower than for a man with the same body values.
- Weight term
- 10 × 59.0 = +590
- Height term
- 6.25 × 162.6 = +1,016
- Age term
- −5 × 28 = −140
- Sex adjustment
- Female −161 → about 1,305 kcal/day
Keep BMR and TDEE separate
Diet planning should anchor on TDEE, the activity-adjusted number, not on BMR itself. Eating below BMR for long stretches risks muscle loss and rebound, so gradual deficits from TDEE are the usual recommendation.
Know the limits of the formula
Mifflin-St Jeor is a statistical model that assumes average body composition. Athletes with high muscle mass tend to be underestimated, and high body-fat percentages can be overestimated.
- Pregnancy, thyroid conditions, and similar cases need medical guidance
- Lean-mass-based formulas such as Katch-McArdle reflect body composition
- This page is an educational estimate, not medical advice
BMR frequently asked questions
What is basal metabolic rate (BMR)?
The minimum daily energy your body uses while awake and fully at rest, covering breathing, temperature regulation, and organ function. Exercise and daily movement are not included.
Which formula does this calculator use?
The Mifflin-St Jeor equation published in 1990: a weight term (10×kg), height term (6.25×cm), and age term (−5×years), plus a sex adjustment of +5 for men or −161 for women.
How do I estimate my total daily calories?
Use the activity table under the result. It multiplies your BMR by factors from 1.2 (sedentary) to 1.9 (extremely active), which approximates total daily energy expenditure (TDEE).
Can I enter pounds and feet/inches?
Yes. The unit selector defaults to lb · ft/in on this page and converts automatically. Internally the math always runs in metric with 1 lb = 0.45359237 kg and 1 in = 2.54 cm.
Can I use the result directly for a diet plan?
Treat it as a starting point. Muscle mass, hormones, and health conditions shift real metabolic rates, and sustained weight-change plans are safer with professional guidance.
Reviewed: 2026-07-11. Activity factors are conventional bands and vary by individual.