Compare adult BMR equations and a selected activity-multiplier TDEE scenario without generating calorie, macro, or meal prescriptions.
A quick decision brief for this specific tool
Adult age 18–100, published equation sex constant, height, weight, selected BMR formula, body-fat percentage when Katch–McArdle is selected, and one activity-multiplier scenario
Selected BMR, Mifflin–St Jeor and revised Harris–Benedict comparison, optional Katch–McArdle estimate, and one activity-multiplier TDEE scenario
The selected adult population BMR equation followed by multiplication by the selected broad activity category
Choose your path
Compare adult population BMR equations and one activity-multiplier TDEE scenario without turning an estimate into a calorie, macro, or meal prescription.
See how a published resting-energy equation and broad activity category combine.
Enter adult measurements, choose a formula and activity scenario, and inspect the formula comparison.
Can name the selected assumptions and does not mistake the output for measured expenditure.
Use Katch–McArdle only when a credible body-fat estimate is available.
Select Katch, enter a valid body-fat value, compare results, then test an invalid value.
The tool requires the extra input and never silently substitutes a different formula.
Avoid an unsupported fixed deficit, surplus, macro split, or meal plan.
Review the result and adult-scope notice after selecting an activity scenario.
Sees only population estimates and understands individualized dietary planning is outside the tool.
This tool is part of these guided projects. Each project provides step-by-step instructions with checklists and all the tools you need in one place.
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BMR estimates resting energy expenditure from height, weight, age, and sex. The calculator uses Mifflin–St Jeor by default and Katch–McArdle only when a valid body-fat percentage is supplied.
Men: BMR = 10×kg + 6.25×cm − 5×age + 5 | Women: BMR = 10×kg + 6.25×cm − 5×age − 161Formula: Mifflin et al., American Journal of Clinical Nutrition (1990)
TDEE is modeled by multiplying estimated BMR by a broad self-selected activity factor. This is a planning heuristic and may not match an individual's measured expenditure.
Estimated TDEE = estimated BMR × activity multiplier (1.2 to 1.9)The calculator intentionally does not generate fixed deficits, surpluses, macro targets, or meal plans. Those decisions depend on health, goals, medications, pregnancy or breastfeeding status, behavior, and measured response.
Output = BMR estimate × selected activity multiplierFor adults 18+ only. It is not intended for pregnancy, breastfeeding, youth, or medical nutrition therapy. Equation-level validation does not guarantee individual accuracy; calibrate against observed trends.
Formula: NIDDK Body Weight Planner scope
Updated: August 2026
Comparing an adult resting-energy equation with a broad light-activity multiplier without setting an intake target.
→ A BMR estimate and an activity-multiplier TDEE scenario
Comparing Mifflin–St Jeor and revised Harris–Benedict estimates while keeping the activity assumption visible.
→ Selected BMR, formula comparison, and TDEE activity scenario
Recording a population-equation estimate as context, not a guarantee of maintenance intake.
→ A sedentary activity-multiplier scenario with method and scope shown
Activity categories are broad heuristics. Choose the description that best matches a typical week, then calibrate the estimate against observed trends instead of assuming the multiplier is exact.
The result combines two population assumptions and does not measure individual expenditure or establish a safe intake. Use qualified guidance for material dietary changes.
Estimate adult resting energy with Mifflin–St Jeor, revised Harris–Benedict, or Katch–McArdle, then apply a broad activity scenario. The result is not measured expenditure or an intake target.