TDEE Calculator
Calculate Total Daily Energy Expenditure (TDEE) — BMR multiplied by an activity factor.
About the TDEE Calculator
Total Daily Energy Expenditure (TDEE) is the total calories your body burns in 24 hours: BMR (resting energy, 60-75%), the thermic effect of food (~10%), exercise activity thermogenesis, and non-exercise activity thermogenesis (NEAT — fidgeting, walking, standing). TDEE is the number you must eat to maintain your current weight; eating below TDEE creates a deficit and eating above creates a surplus.
Direct measurement of TDEE requires a doubly-labelled water protocol that costs roughly $1,000 per measurement. The standard estimate combines Mifflin-St Jeor BMR with an activity multiplier. The five multipliers used here — 1.2, 1.375, 1.55, 1.725, 1.9 — were popularised by Harris and Benedict and are widely cited in nutrition textbooks and the Academy of Nutrition and Dietetics’ position papers.
Selecting the right activity factor is the largest source of error in the estimate. Most adults overestimate their activity level by one band, which inflates TDEE by 150-250 kcal/day and undermines weight-loss planning. Choose conservatively: a desk worker who exercises 3×/week is usually Lightly active, not Moderately active.
How It Works
TDEE = BMR × activity multiplier. We use the Mifflin-St Jeor equation for BMR (1990, PMID 2305711) and the five conventional multipliers:
Sedentary (desk job, <5,000 steps/day) 1.2
Lightly active (1-3 days/week light exercise) 1.375
Moderately active (3-5 days/week moderate) 1.55
Very active (6-7 days/week hard exercise) 1.725
Extra active (athlete / physical job) 1.9The multipliers reflect the contribution of activity thermogenesis on top of resting metabolism. Sedentary multiplier 1.2 means TDEE is 20% above BMR — barely above resting — while Extra active multiplier 1.9 means TDEE is 90% above BMR, the level of a labourer or endurance athlete.
To lose 0.5 kg/week, subtract 500 kcal/day (since 0.5 kg of body fat ≈ 3,500 kcal). To gain 0.5 kg/week, add 500 kcal/day. Use our Calorie Calculator for guided targets and floor checks.
Worked Examples
A 30-year-old man, 75 kg, 178 cm, BMR 1,717 kcal/day:
- Sedentary (office job, no exercise): 1,717 × 1.2 = 2,061 kcal/day
- Moderately active (gym 3×/week): 1,717 × 1.55 = 2,661 kcal/day
- Very active (manual labour + gym): 1,717 × 1.725 = 2,962 kcal/day
The spread is 900 kcal/day — the difference between maintenance at 2,061 and maintenance at 2,962. Misclassifying as “very active” when actually sedentary would over-estimate TDEE by ~900 kcal/day and stall any weight-loss plan.
A 35-year-old woman, 62 kg, 165 cm, BMR 1,315 kcal/day: lightly active TDEE = 1,808 kcal/day. To lose 0.5 kg/week she targets 1,308 kcal/day — just above the ~1,200 kcal floor for women without supervision.
Endurance athletes in heavy training can sustain TDEE above 4,000 kcal/day; mountaineers on multi-week expeditions have measured TDEE of 6,000-7,000 kcal/day, requiring deliberate fuelling strategies.
When to Use This Tool
- Compute maintenance intake before designing a cut, bulk, or recomp nutrition plan.
- Diagnose weight-loss plateaus — recheck TDEE after significant weight change.
- Compare estimated TDEE against wearable-device (Apple Watch, Fitbit, Whoop) calorie readings, which typically differ by 5-20%.
- Set macros for sports nutrition — endurance athletes need higher carb ratios at high TDEE.
- Adjust calories during pregnancy (add ~340 kcal/day in 2nd trimester, ~452 in 3rd — ACOG).
- Plan nutrition for hiking, climbing, or expedition trips where TDEE can hit 4,000-5,000 kcal.
- Estimate feeding requirements for hospitalised patients on bed rest or post-surgery.
Limitations & Disclaimer
The activity multipliers are population averages with wide individual variation; NEAT alone varies by 200-500 kcal/day between individuals at the same nominal activity level. Wearable devices may differ from this estimate by 5-27%. This tool is not medical advice and is not a substitute for individualised clinical assessment. See our disclaimer for full terms.
Frequently Asked Questions
Which activity level should I pick?
Most adults overestimate. Sedentary = desk job, <5,000 steps/day, no exercise. Lightly active = 1-3 light workouts/week OR 7,500-10,000 steps. Moderately active = 3-5 moderate workouts/week OR 10,000-12,500 steps. Very active = 6-7 hard workouts or a physical job. Extra active = competitive athlete or heavy manual labour. When in doubt, round down.
Why does my fitness tracker show a different TDEE?
Wearable devices estimate TDEE from heart rate and accelerometry, with model-specific corrections. Validation studies show errors of 5-27% depending on activity. The most accurate consumer approach remains indirect calorimetry performed in a clinic.
Should I use this for medical nutrition therapy?
Only as a starting point. Clinical dietitians adjust for fever, surgery, burns, cancer, HIV, sepsis, and critical-care status using condition-specific equations (Penn State, Faisy, Brandi). For clinical use, consult a registered dietitian.
How often should I recalculate TDEE?
Every 5 kg of weight change, every 5 years of ageing, or whenever activity level shifts by one band. BMR falls ~1-2% per decade after 20, and weight changes shift the formula nonlinearly.
Is the 3,500-kcal rule for 0.5 kg loss accurate?
Approximately. One pound (0.454 kg) of adipose tissue contains ~3,500 kcal of recoverable energy, but metabolic adaptation reduces the deficit over time. Modern dynamic models (Hall et al., NIH) predict sustained 500 kcal/day deficits yield ~0.4 kg/week initially, decelerating over months.
Does pregnancy change TDEE?
Yes. Per ACOG, pregnant women need ~340 extra kcal/day in the 2nd trimester and ~452 extra in the 3rd, on top of pre-pregnancy TDEE. Lactation adds another ~500 kcal/day. See our <a href="/tools/pregnancy-weight-gain.php">Pregnancy Weight Gain Calculator</a>.
Last updated: September 9, 2026 · Author: HT99 Tools Editorial Team