Explain it like I'm 12
The BMR calculator estimates resting energy needs from weight, height, age and equation sex using the Mifflin-St Jeor formula.
Health & Fitness
BMR Calculator
Estimate basal metabolic rate using the Mifflin-St Jeor equation, with Harris-Benedict comparison and daily context.
Calculator
Working calculator
Live result1,743 kcal/dayMifflin-St Jeor: 10×80 + 6.25×178 - 5×35 + 5. Resting estimate only.
Formula used
BMR = 10 × weight kg + 6.25 × height cm − 5 × age years + S, where S is +5 for the male equation and −161 for the female equation.
This is the method behind the answer, so the result can be checked rather than simply trusted.Visual grid
This number is one point on a larger pattern
BMR is not just a final answer. It is a step on a line: before and after, input and output, assumption and result.
Micro-timehours, minutes, shiftsHuman scaledays, weeks, projectsMacro-timemonths, years, calendars
InputFormulaResult
1,743 kcal/dayCalculationTime keeps the path visible: the input, the method and the final number belong together.
CalculationTime
BMR Calculation Report
1,743 kcal/dayMifflin-St Jeor: 10×80 + 6.25×178 - 5×35 + 5. Resting estimate only.
Inputs
- Sex for equation
- Male equation
- Age
- 35 years
- Weight
- 80 kg
- Height
- 178 cm
Method
BMR = 10 × weight kg + 6.25 × height cm − 5 × age years + S, where S is +5 for the male equation and −161 for the female equation.
- An 80 kg, 178 cm, 35-year-old using the male equation gives 10×80 + 6.25×178 − 5×35 + 5 = 1,742.5 kcal/day.
Assumptions
- BMR is an estimate of resting energy use, not total daily expenditure.
- The equation is population-based and can be less accurate for unusual body composition or clinical conditions.
- Use TDEE for activity-adjusted estimates.
Notes
Use this space on the printed report for client, supplier, classroom, job-location, measurement, quote or approval notes.
Source references
- Mifflin et al. resting metabolic rate equation — BMR equation source
Formula
BMR = 10 × weight kg + 6.25 × height cm − 5 × age years + S, where S is +5 for the male equation and −161 for the female equation.
Worked example
An 80 kg, 178 cm, 35-year-old using the male equation gives 10×80 + 6.25×178 − 5×35 + 5 = 1,742.5 kcal/day.
Professional note
Master’s Tip: BMR is the floor estimate. Multiply by activity to estimate total daily energy expenditure.
Regional and unit assumptions
Mifflin-St Jeor metric equation. Health education only.
Assumptions and limitations
- BMR is an estimate of resting energy use, not total daily expenditure.
- The equation is population-based and can be less accurate for unusual body composition or clinical conditions.
- Use TDEE for activity-adjusted estimates.
Methodology & Accuracy
How this calculator is checked
CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.
Formula used
BMR = 10 × weight kg + 6.25 × height cm − 5 × age years + S, where S is +5 for the male equation and −161 for the female equation.
Standard or basis
Mifflin-St Jeor metric equation. Health education only.
Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.Master's Tip
Master’s Tip: BMR is the floor estimate. Multiply by activity to estimate total daily energy expenditure.
Related calculators
Questions
Is BMR the same as maintenance calories?
No. Maintenance calories include movement and activity; BMR is a resting estimate.
Why does the equation use sex?
The published formula uses different constants to approximate average body-composition differences.