How to use the metric katch mcardle calculator
Prepare the values for this calculation
Estimate adult resting energy expenditure using the Katch–McArdle equation. Use the formula below to check that it answers your question. Read the input units before transferring figures from a statement, measurement or dataset.
Enter and check each input
- Body weight (kg): enter a value at least 20 and no more than 400. Use the unit named in the label or selected above. Do not leave this required field blank.
- Body fat (%): enter a value at least 0 and no more than 80. Use the unit named in the label or selected above. Do not leave this required field blank.
The input table gives a complete example. Keep units and time periods consistent across related fields.
Calculate and resolve any input error
Choose Calculate after entering the values. Changes also update the answer after a short pause. If an error appears, follow its message, correct the field and calculate again. Reset restores the example values.
Interpret the answer
Check Estimated resting energy first. With the unchanged example inputs, it is 1,666 kcal/day. Compare the additional metrics with the primary result; each has its own label and unit.
Compare and keep a useful result
For a controlled comparison, keep every other example input unchanged and change Body weight (kg) from 75 to 82.5. The resulting Estimated resting energy is 1,795.6 kcal/day. This illustrates the equation’s response to that input, rather than a forecast of real events.
Read the chart’s axis labels and data table. A scenario curve changes one stated input while holding the others fixed; it does not add external observations. Use Download graph to save an available chart as a PNG.
Use Copy result or Download CSV to keep the answer. Share tool shares the page address without placing your input values in the URL. Recheck inputs and assumptions before using the result for a decision.
Metric Katch McArdle Calculator formula
Katch–McArdle: resting energy=370+21.6×lean body mass(kg), with lean mass=weight×(1−body-fat fraction).
Inputs and units
| Input | Format / range | Example |
|---|---|---|
| Body weight (kg) | minimum 20; maximum 400 | 75 |
| Body fat (%) | minimum 0; maximum 80 | 20 |
Worked example
Using the example inputs above, the estimated resting energy is 1,666 kcal/day.
- Estimated resting energy
- 1,666 kcal/day
- Estimated lean body mass
- 60 kg
- Equation
- Katch–McArdle
Results and assumptions
Educational estimate only; prediction equations do not replace indirect calorimetry, clinical assessment, or individualized medical advice.
Sources and method references
Fix an input or unexpected result
Body weight (kg) is required. Enter body weight (kg) using the format and bounds in the input table. Zero and an empty field are different: use zero only if it is allowed and represents your data.
If your answer differs from the example, choose Reset and compare every field, including selected units and options. Check percentage versus decimal entry and whether values describe the same period. Round only the final displayed answer when reproducing the formula.
If a discrepancy remains, report the calculator issue with the page address, non-sensitive example inputs, actual result, expected result and a reference for your calculation.