Sourced calculator and guide
RMR calculator: estimate resting energy
Estimate resting energy expenditure (REE, often called RMR). This BMR calculator route reports an estimate of REE, not a laboratory measurement of basal metabolic rate.
Calculate your estimate
Enable JavaScript to edit inputs. The worked examples below remain available without it.
Confirm the adult scope before calculating. This tool excludes pregnancy and breastfeeding.
Worked examples from the same calculator
Unless the row says otherwise: age 30, 70 kg, 175 cm, male coefficient. Only the final output is rounded using decimal half-up rules.
| Input scenario | Estimate |
|---|---|
| Male coefficient, age 30 | 1649 kcal/day |
| Female coefficient, age 30 | 1483 kcal/day |
| Male coefficient, age 50 | 1549 kcal/day |
RMR versus BMR
Basal measurements require strict basal conditions; resting measurements use resting conditions. The original Mifflin study predicted resting energy expenditure, measured by indirect calorimetry. Calling this a BMR calculator does not turn its output into measured BMR.
Who the equation studied
The original study included 498 healthy adults, ages 19–78, including normal-weight and obese participants. This tool accepts whole-year ages in that range and excludes children, pregnancy and breastfeeding. Its two sex coefficients reproduce the study; their suitability outside that population is uncertain.
How precise is the resting estimate?
Individual error can be substantial. The source does not establish a universal personal confidence interval, so this calculator does not invent a ±10% band. The result is neither a daily food prescription nor total daily energy expenditure.
Source formulas and scope
The simplified equations in the original Mifflin–St Jeor PubMed abstract read:
REE (males) = 10 x weight (kg) + 6.25 x height (cm) - 5 x age (y) + 5; REE (females) = 10 x weight (kg) + 6.25 x height (cm) - 5 x age (y) - 161.
Output is estimated REE in kcal/day. Original study: 498 healthy adults, ages 19–78. This tool excludes children, pregnancy and breastfeeding; it provides no medical advice. The equation’s two coefficients reflect the study, and do not establish validation for other populations. US inputs use exactly 1 lb = 0.45359237 kg and 1 in = 2.54 cm without intermediate rounding. Other maximum input limits only prevent extreme or accidental entries; they are not clinical thresholds.
Questions and answers
Does this RMR calculator measure my BMR?
No. It estimates resting energy using the simplified Mifflin–St Jeor equations. A measurement requires an appropriate assessment such as indirect calorimetry.
Does the RMR estimate include exercise?
No. The resting result has no activity multiplier. Use the separate maintenance guide to examine explicitly chosen PAL assumptions.
Sources
Reviewed October 29, 2026. Original formulas are quoted above; derived scenario arithmetic is identified separately.