Harris–Benedict Calculator | Revised 1984 REE Equation

Harris and Benedict published historical basal-energy regressions in December 1918 and expanded their work in the 1919 monograph. This form uses the revised coefficients from Roza and Shizgal’s July 1984 paper, not the historical coefficient set.

Basal measurement uses controlled resting and post-absorptive conditions. Resting-energy prediction instead substitutes inputs into a regression equation. FAO/WHO/UNU definitions distinguish basal conditions and total expenditure. This form does not perform calorimetry.

Total daily expenditure includes energy beyond rest. A selected numerical product is not a measurement of that expenditure, a minimum food allowance, or a verified maintenance intake. There is no fixed percentage gap between the displayed equations.

Enter weight, height and age in the displayed units, then select the male or female coefficient set used in the source. These labels identify equation coefficients, not a measurement of body composition. Inputs must be complete finite numbers; results are cleared when contributing inputs change.

Metric inputs use kg and cm. Where imperial choices are present, pounds are multiplied by 0.45359237 and inches by 2.54 before calculation. Displayed kcal/day is rounded to a whole number.

Revised Harris–Benedict (Roza–Shizgal, July 1984): men: REE = 88.362 + 13.397 × W + 4.799 × H − 5.677 × A; women: REE = 447.593 + 9.247 × W + 3.098 × H − 4.330 × A. W is kg, H is cm and A is years; output is kcal/day. Original paper, Table 3, equations 3 and 6.

For a male coefficient example with 70 kg, 175 cm and age 30: 88.362 + 13.397 × 70 + 4.799 × 175 − 5.677 × 30 = 1,695.667 kcal/day, displayed as 1,696. The female coefficients at the same inputs give 1,507.133 kcal/day, displayed as 1,507.

The original 1918 coefficients are men: 66.4730 + 13.7516 × W + 5.0033 × H − 6.7550 × A; women: 655.0955 + 9.5634 × W + 1.8496 × H − 4.6756 × A. Original paper, page 373. These historical values are context, not a second automatically selected result.

Use the form to reproduce the named equation, verify a unit conversion, or compare coefficient sets in the original papers. A separately selected factor such as 1.2 gives the mathematical product REE × 1.2; exercise days do not validate that factor for a person.

Equation output is predicted resting energy, not measured metabolism or a food-intake target. No automatic deficit, surplus, macronutrient prescription, weekly weight forecast, or medical metabolism grade is inferred.

A study population describes the evidence behind an equation. It does not establish suitability for every person with the same age or measurements, or for illness, pregnancy, lactation, or childhood. Individual nutrition decisions require information beyond these inputs.

The retained revised equations use 337 historical subjects, including older adults. The paper discusses malnutrition-related limitations. No age ceiling of 70 is inferred from the older paper’s prediction tables, and no universal accuracy or revised-model superiority is promised.

Positive finite operands and outputs protect the arithmetic. They do not establish that a model is appropriate for a particular individual or life stage.

Publication: Roza and Shizgal, July 1984, DOI 10.1093/ajcn/40.1.168. The retained coefficients come from Table 3, equations 3 and 6, based on 337 historical subjects including older adults. The paper reports limits for malnourished patients; its study statistics are not individual guarantees.

Historical context: Harris and Benedict (December 1918), original paper, page 373. The adult series had 136 men and 103 women. The tabulated ages 21–70 are not universal validation bounds. Sources checked on 2026-09-30.

NIST Handbook 44 (2026), Appendix C: 1 lb = 0.45359237 kg; 1 in = 2.54 cm.