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Nutrition

TDEE Calculator

Estimate your total daily energy expenditure with Mifflin-St Jeor and standard activity multipliers.

Your numbers

Start from an example

Units
Biological sex
Age
Weight (kg)
Height (cm)
Activity level
Body fat % (optional)

Optional. With it, the Katch-McArdle formula joins the estimate.

Training days per week (optional)

Optional. Splits the same weekly total into training-day and rest-day calories.

Result

Maintenance calories (TDEE)
2,759kcal/day
BMR
1,780kcal/day
Activity factor
1.55
Range across formulas
2,759–2,873kcal/day

Daily calories by goal

Lose about 0.45 kg a week
2,259kcal/day
Maintain weight
2,759kcal/day
Lean gain (+300 kcal)
3,059kcal/day

Energy needs snapshot

BMR is the floor; TDEE adds activity-driven calorie lift.

BMR
1,780 kcal/day
TDEE
2,759 kcal/day
Activity lift
979 kcal/day

Formula from Mifflin-St Jeor (1990) and Pontzer energy-expenditure (2021), checked against the source on May 25, 2026.

Education, not medical advice. The result comes only from the published formula and your inputs. How we check our formulas.

What does the TDEE Calculator calculate, and which formula does it use?

The TDEE Calculator estimates total daily energy expenditure by computing BMR with up to four published equations — Mifflin-St Jeor (10 × weight + 6.25 × height − 5 × age, +5 men / −161 women) as the primary, revised Harris-Benedict, Katch-McArdle when body fat is supplied, and WHO/FAO/UNU — then multiplying by an activity factor from 1.2 (sedentary) to 1.9 (athlete).

Last updated .

How to use it

  1. Pick Metric or US units, then enter your current weight, height, age and sex. The headline uses Mifflin-St Jeor; Harris-Benedict and WHO/FAO/UNU run alongside it as a cross-check.
  2. Select your activity level honestly — most people overestimate by one tier. When in doubt, go one tier lower. Adding body fat % brings in Katch-McArdle; adding training days splits the week into training-day and rest-day calories.
  3. Read the range across formulas under the headline. A wide range (>400 kcal) means your profile is harder to estimate; adding body fat % usually narrows it.
  4. Use the daily calories by goal: maintain, a 500 kcal deficit (about 1 lb a week at first) or a 300 kcal lean gain. Take that number to the Macro Calculator to split it into protein, carbs and fat.
  5. Treat the result as a starting point: hold it for 2-3 weeks, compare against your scale trend, and adjust. Re-run after any 2+ kg (5 lb) weight change.

Questions people usually ask

How accurate is the Mifflin-St Jeor equation?

Within 10-15% for most people. The formula assumes average body composition — it overestimates for high-body-fat individuals and underestimates for very lean or muscular people. Track your actual intake vs weight for 2-3 weeks to calibrate.

Why does my TDEE seem too high?

Most people overestimate their activity level. Try one tier lower (e.g., Moderately Active → Lightly Active) and track food intake for 2 weeks. If you are gaining weight at the calculated TDEE, your true maintenance is lower.

What is the difference between TDEE and BMR?

BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — just to keep organs functioning. TDEE multiplies BMR by an activity factor (1.2 for sedentary up to 1.9 for twice-daily training) to estimate total daily burn including movement.

How do I use TDEE to lose weight?

Create a 300-500 calorie daily deficit from your TDEE. This yields roughly 0.5-1 lb per week of loss. Deficits larger than 25% of TDEE accelerate muscle loss and metabolic adaptation — slower is more sustainable.

Should I eat at TDEE on rest days and more on training days?

Either approach works. Eating at TDEE daily (with the correct activity multiplier) is simpler. Carb cycling (more on training days, less on rest days) can improve performance but adds complexity without proven fat-loss advantage for most people.

How often should I recalculate my TDEE?

Recalculate every 4-6 weeks or after any 5 lb change in body weight. TDEE drops as you lose weight — a 10 lb loss typically reduces TDEE by 50-100 calories. This is why calorie targets must decrease during a cut.

  • Formula TDEE Formula

    TDEE = BMR × activity factor. Factors: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active, 1.9 athlete. Drives fat-loss deficit and lean-gain surplus math.

  • Formula Female Athlete Formula Suite

    Female athlete energy availability (RED-S): EA = (intake_kcal − exercise_kcal) / FFM_kg, where EA below 30 kcal/kg is clinically low per IOC 2018 consensus.

  • Formula Hybrid Athlete Macro Split Formula

    Hybrid athlete macro split formula: protein 1.8-2.2 g/kg by lifting sessions, carbs 4-7.5 g/kg on training days by weekly run distance, fat 0.9-1.0 g/kg.

Background on the TDEE Calculator

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By goal

Use it from code

The same calculation as a JavaScript module you can import. It runs where you import it, with no request, key or rate limit.

import { compute } from "https://aifithub.io/engines/tdee-calculator.js";

Input and output contract, TypeScript types and the guide for agents.