Purpose and steps
Uses the Mifflin–St Jeor equation to estimate daily resting energy expenditure from weight, height, age, and the sex term used by the equation.
- Choose units and use the pre-pregnancy, resting or current measurements requested by the tool; keep observation dates consistent.
- Prepare Sex used by the equation, Age, Weight, Height. Defaults demonstrate the model rather than your personal circumstances.
- Check the headline result and its components. A key interpretation for this tool is: BMR estimates energy used at rest before daily activity or exercise.
- Compare the baseline with a changed scenario: Use a TDEE calculator when you need an estimate that includes activity.
Input reference and units
These values reproduce the model’s demonstration. Replace them with your own records or measurements; they are not recommended targets.
On a small screen, swipe the table horizontally to see all columns.
| Parameter | Demonstration value | How to enter it |
|---|---|---|
| Sex used by the equation | Female | Use the definition shown in the field label; keep this assumption consistent when comparing scenarios. |
| Age | 30 years | Use years here. The model converts to months when the payment schedule requires it. |
| Weight | 70 kg | Use the definition shown in the field label; keep this assumption consistent when comparing scenarios. |
| Height | 170 cm | Use the definition shown in the field label; keep this assumption consistent when comparing scenarios. |
Model-specific method
How this calculator produces its result
Mifflin–St Jeor: women = 10W + 6.25H − 5A − 161; men = 10W + 6.25H − 5A + 5, with kg, cm, and years.
Empirical equations are fitted estimates
A fitted formula summarizes a relationship observed in a study population. Coefficients such as calories per kilogram are not universal laws. Use the prescribed units, population and inputs; a model derived from adults may be unsuitable for children or pregnancy.
Averaging several formula outputs summarizes their center but does not remove their shared limitations. Likewise, showing a result to one decimal place does not mean the real-world quantity is known to that precision. Compare estimates with observations and discuss health decisions with qualified care staff.
Linear model: y = a + b₁x₁ + b₂x₂ + … Arithmetic mean = sum of estimates / number of estimates Prediction error ≠ display-rounding error
- a: fitted intercept
- b: fitted coefficient with its own unit
- x: measured input in the equation’s required unit
- Prediction: estimate within the model’s intended population
Worked example
For a 30-year-old woman at 70 kg and 170 cm: 700 + 1,062.5 − 150 − 161 = about 1,452 kcal/day.
Reproduce the default scenario
This is a separate example, calculated using the exact engine on the tool page and the defaults in the input reference above. Health examples use metric units. Displayed rounding may differ from intermediate precision.
- BMR
- 1,452 kcal/day
- Hourly average
- 60 kcal/hour
Reading results without overstating them
- BMR estimates energy used at rest before daily activity or exercise.
- Use a TDEE calculator when you need an estimate that includes activity.
Assumptions and exclusions
- Individual metabolism can differ because of body composition, health, and measurement conditions.
- The sex term is part of the published equation and does not capture every individual.
Sources and content notes
Toolify describes the implemented algorithm and its assumptions. Sources below support the topic or applicable rules; they do not endorse this calculator. Examples are illustrative, and published rules take precedence over simplified estimates.
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