Energy Expenditure & Metabolic Calculators
Explore our complete suite of scientifically validated calculators. From full Total Daily Energy Expenditure (TDEE) models to specialized Fat-Free Mass (FFM) and Basal Metabolic Rate (BMR) equations.
Our full 4-pillar Total Daily Energy Expenditure engine. Calculate your exact maintenance calories, dynamic cutting deficits, lean bulking surpluses, macronutrient distribution, calorie cycling, and weekly weight-change timelines.
Complete daily nutrition planning, goal setting (fat loss/muscle gain), calorie cycling, and macro tracking.
The gold-standard clinical equation recommended by the Academy of Nutrition and Dietetics. Estimates resting metabolic rate from weight, height, age, and sex with exceptional accuracy across diverse adult populations.
General population metabolic baselines when body fat percentage is unknown or unmeasured.
Estimates resting energy expenditure directly from Fat-Free Mass (FFM). Includes our FFM-anchored daily macronutrient generator, Normalized FFMI barometer, and interactive 'Future You' body recomposition sandbox.
Individuals with known body composition, DEXA scan readings, or measurable body fat percentages.
The original 1980 Cunningham equation regressing resting expenditure directly against lean body mass. Features integrated Physical Activity Level (PAL) TDEE estimation, FFM-anchored protein targets, and body-fat sensitivity analysis.
Resistance-trained lifters, athletic competitors, and muscular individuals seeking an FFM-anchored baseline.
The world's most famous historical metabolic equation, modernized with the 1984 Roza and Shizgal biometric revision. Explore step-by-step arithmetic and direct comparison against modern formulas.
Comparative metabolic analysis, academic reference, and historical equation benchmarking.
The standard equation adopted by the World Health Organization (WHO), FAO, and United Nations University. Calculates BMR using 6 discrete age-group regression tiers (0–3, 3–10, 10–18, 18–30, 30–60, 60+).
Global population studies, adolescent nutrition, senior metabolic assessment, and WHO guideline compliance.
Calculates Resting Energy Expenditure (REE) directly from body weight and biological sex without needing height or age. Based on the classic 1986 (women) and 1987 (men) clinical indirect calorimetry studies.
Weight-based resting energy assessment, quick REE benchmarking, and comparative metabolic studies.
The gold-standard modern BMR update (N=10,552) developed to replace older Schofield equations. Eliminates the historical Italian cohort overestimation and accurately predicts BMR across 6 biological life stages.
Modern basal energy assessment, UK SACN & PENG guideline compliance, and eliminating older equation overestimations.
Metabolic Calculator Comparison Matrix
How to choose the optimal energy expenditure equation for your body and goals
| Calculator | Primary Formula | Required Inputs | Body Fat Factor | Recommended Use Case |
|---|---|---|---|---|
| Master TDEE | Multi-Model Engine | Weight, Height, Age, Sex, Activity | Optional (Auto-adjusts) | Full 24-hour calorie targets, cutting/bulking plans, and macro cycling. |
| Mifflin–St Jeor | 10W + 6.25H − 5A + s | Weight, Height, Age, Sex | Not used (Stature-based) | Clinical standard for general population when body composition is unknown. |
| Katch–McArdle | 370 + (21.6 × FFM) | Total Weight + Body Fat % OR FFM | Essential (100% FFM) | Individuals with known body composition from DEXA scans or calipers. |
| Cunningham (1980) | 500 + (22.0 × FFM) | Total Weight + Body Fat % OR FFM, PAL | Essential (100% FFM) | Resistance-trained athletes and heavy lifters seeking an FFM baseline. |
| Revised Harris–Benedict | Roza & Shizgal 1984 | Weight, Height, Age, Sex | Not used (Stature-based) | Historical equation benchmarking against modern clinical models. |
| Schofield (WHO) | WHO 6 Age-Group Tiers | Weight, Age Bracket, Sex | Not used (Age-tiered) | Global public health studies, senior nutrition, and WHO dietary compliance. |
💡 How to Pick the Right Calculator for Your Fitness Goals:
- If you don't know your body fat %: Use the Mifflin–St Jeor Calculator or our Master TDEE Calculator. They calculate your metabolic rate reliably using age, sex, height, and weight.
- If you know your body fat % or have a DEXA scan: Use the Katch–McArdle Calculator or Cunningham Calculator to anchor your daily energy needs strictly to your fat-free mass.
- If you want full 24-hour calorie targets: Use the Master TDEE Calculator to configure calorie deficits, surplus targets, training day cycling, and macronutrient targets.