Skip to content

Calorie Calculator

Compare adult BMR equations and a selected activity-multiplier TDEE scenario without generating calorie, macro, or meal prescriptions.

Use this result well

Inputs that matter
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
Output to expect
Selected BMR, Mifflin–St Jeor and revised Harris–Benedict comparison, optional Katch–McArdle estimate, and one activity-multiplier TDEE scenario
How it works
The selected adult population BMR equation followed by multiplication by the selected broad activity category
  • This adult population estimate is not measured expenditure and is not intended for youth, pregnancy, breastfeeding, or medical nutrition therapy.
  • The tool deliberately generates no intake target, fixed deficit/surplus, macro target, or meal plan; use qualified individualized guidance for those decisions.

Choose your path

Built around the job you need to finish

Compare adult population BMR equations and one activity-multiplier TDEE scenario without turning an estimate into a calorie, macro, or meal prescription.

Adult seeking equation context

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.

Body-fat informed user

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.

User asking for an intake target

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.

Was this tool helpful?

Reference & details

How it works

Basal Metabolic Rate (Mifflin-St Jeor)

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 − 161

Source: Mifflin et al., American Journal of Clinical Nutrition (1990)

Total Daily Energy Expenditure (TDEE)

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)

No Intake Prescription

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 multiplier

Adult Planning Scope

For 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.

Source: NIDDK Body Weight Planner scope

Updated: August 2026

Example Scenarios

Comparing an adult resting-energy equation with a broad light-activity multiplier without setting an intake target.

Weight: 70 kgHeight: 168 cmAge: 32Activity: Light (1.375×)

A BMR estimate and an activity-multiplier TDEE scenario

Comparing Mifflin–St Jeor and revised Harris–Benedict estimates while keeping the activity assumption visible.

Weight: 75 kgHeight: 180 cmAge: 25Activity: Very active (1.725×)

Selected BMR, formula comparison, and TDEE activity scenario

Recording a population-equation estimate as context, not a guarantee of maintenance intake.

Weight: 65 kgHeight: 172 cmAge: 40Activity: Sedentary (1.2×)

A sedentary activity-multiplier scenario with method and scope shown

Common Mistakes to Avoid

Overestimating activity level

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.

Treating the TDEE scenario as a calorie prescription

The result combines two population assumptions and does not measure individual expenditure or establish a safe intake. Use qualified guidance for material dietary changes.

FAQ

Total Daily Energy Expenditure is the total calories you burn in a day, including BMR, physical activity, digestion, and daily movement. TDEE = BMR × activity multiplier, typically ranging from 1.2 (sedentary) to 1.9 (very active).

It cannot determine that. The tool does not generate a deficit or intake target because an appropriate plan depends on individual health, goals, medications, activity, and response.

Use the description that best matches your typical week: sedentary uses 1.2× BMR and lightly active uses 1.375×, with higher tiers for more frequent activity. The categories are rough planning factors, so compare the estimate with your real trend.

Mifflin–St Jeor performed comparatively well among commonly used equations in validation research, but individual errors remain and an activity multiplier adds more uncertainty. Use the result as a starting point and calibrate it against real-world trends.

A systematic review found Mifflin–St Jeor more reliable than other commonly used predictive equations across the included studies, while still noting clinically meaningful individual error. This calculator therefore uses it by default and shows Harris–Benedict as a comparison.

About Calorie Calculator

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.