What next?
TDEE is the number every diet target is derived from. These apply it.
What your result means
TDEE is the total energy you burn in an average day: your resting metabolism plus movement, exercise and the energy used digesting food. Eat consistently at this level and weight stays roughly stable. The targets below apply a moderate deficit or surplus — around 500 kcal below TDEE loses roughly half a kilo a week, which is the pace most guidelines consider sustainable.
Why this one is different
Metric and imperial both, and the activity multiplier is shown as a number you can see and argue with rather than an invisible adjustment inside the result. The Mifflin-St Jeor basis is named and linked, and the worked example below is computed by script against the live tool so the figures are proven to match.
Almost everyone overestimates their activity multiplier
The multipliers describe your whole week, not your best day. Three gym sessions plus a desk job and a car commute is "lightly active", not "very active" — the sedentary hours dominate. Picking a level too high is the most common reason a calorie target quietly fails.
A better method: choose the level you think fits, eat at that target for three weeks, and weigh yourself at the same time each morning. If the trend line is flat, the multiplier was right. Real data beats any equation.
How it works
The calculator first estimates BMR with the Mifflin-St Jeor equation, then multiplies it by an activity factor between 1.2 and 1.9. That factor bundles together deliberate exercise, incidental movement and the thermic effect of food into a single lifestyle coefficient.
How to use this calculator
- Choose your units and enter age, sex, height and weight.
- Pick the activity level that describes your typical week — err low.
- Read your TDEE as your maintenance figure.
- Use the cut or gain target as a starting point and adjust after three weeks of real data.
Formula
BMR from Mifflin-St Jeor. Factors: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active, 1.9 athlete.
Example calculation
A 30-year-old man, 178 cm, 78 kg, lightly active:
TDEE = 1,748 × 1.375
TDEE ≈ 2,403 kcal/day
Cutting target ≈ 1,903 kcal
Frequently asked questions
Why does my fitness tracker show a different number?＋
Trackers estimate from heart rate and step data, which captures your actual day rather than an average. They tend to run high on active days and low on rest days. Compare the weekly average, not a single day.
How big a deficit is safe?＋
Most guidance suggests 10–20% below TDEE, roughly 300–600 kcal for a typical adult. Larger deficits cost muscle and adherence without speeding fat loss proportionally.
Do I need to recalculate as I lose weight?＋
Yes. TDEE falls as body mass falls. Recalculate after every 4–5 kg of change, or whenever progress stalls for more than a fortnight at a consistent intake.
Which activity level should I choose?＋
Pick the one that matches your whole week, including work. Most desk-based people who train three times a week fall in the light-to-moderate band, not the high one.
What is NEAT and why does it matter?＋
Non-exercise activity thermogenesis covers fidgeting, walking and everything that is not deliberate training. It varies by hundreds of calories between people and tends to fall during a diet, which is one reason progress slows.
How do I check my real TDEE?＋
Track intake and weight for two to three weeks at a steady intake. If weight is flat, that intake is your TDEE. This is more accurate than any equation.
Can I use TDEE to gain weight?＋
Yes. A surplus of about 250-400 kcal a day supports gradual gain while limiting fat, provided training and protein intake back it up.
Related calculators
Assumptions & limitations
Every figure here comes from a simplified model. Keep these limits in mind when reading your result:
- Activity multipliers are broad averages; individual variation of several hundred calories a day is normal.
- Assumes typical body composition — athletes with high muscle mass will burn more than predicted.
- Does not account for medical conditions, medication, pregnancy or breastfeeding.
- Targets are general guidance, not a prescribed diet plan.