TDEE Calculator
Daily calories you burn (and need)
Find your Total Daily Energy Expenditure (TDEE) — the calories you burn per day — plus targets to maintain, lose or gain weight. Based on the Mifflin-St Jeor equation.
BMR and TDEE
As a calorie calculator this answers one question: your maintenance calories, sometimes called daily calorie needs, and what to eat above or below them.
BMR is what your body burns at complete rest — keeping you alive and nothing else. TDEE multiplies BMR by an activity factor to estimate what you burn across a whole day including movement, exercise and digesting food.
This calculator uses the Mifflin-St Jeor equation, which is the one most commonly recommended for general use:
BMR = 10 × kg + 6.25 × cm − 5 × age + 5 (men), or − 161 (women).
Estimates only, and not medical or dietary advice. Individual energy needs vary considerably. Speak to a clinician or registered dietitian before making significant changes, particularly if you have any health condition.
Activity multipliers, and why most people pick too high
| Activity level | Multiplier | Describes | Maintenance |
|---|---|---|---|
| Sedentary | 1.2 | Desk job, little deliberate exercise | 2,085 |
| Lightly active | 1.375 | Desk job plus 1 to 3 sessions a week | 2,389 |
| Moderately active | 1.55 | 3 to 5 sessions a week | 2,693 |
| Very active | 1.725 | 6 to 7 sessions, or a physical job | 2,997 |
| Athlete | 1.9 | Twice-daily training or heavy manual work | 3,301 |
The gap between sedentary and athlete on the same body is 1,216 calories a day, so this single dropdown matters more than every other input combined. It is also where nearly everyone overestimates: a desk job with three gym sessions a week is lightly active, not "very active". Choosing one level too high builds a 300-calorie error into the target, which is enough to erase a deficit entirely.
When in doubt, pick the lower option. It is far easier to add calories after two weeks of unexpectedly fast progress than to work out why nothing is happening.
Deficits, surpluses and the 3,500 rule
A pound of body fat stores roughly 3,500 calories, so a 500-calorie daily deficit is often quoted as one pound a week. It is a useful approximation with real limits.
| Goal | Daily change | Target | Rough rate |
|---|---|---|---|
| Weight loss | −500 | 1,889 | ~1 lb/week |
| Mild loss | −250 | 2,139 | ~0.5 lb/week |
| Maintenance | — | 2,389 | Stable |
| Mild gain | +250 | 2,639 | ~0.5 lb/week |
| Weight gain | +500 | 2,889 | ~1 lb/week |
The 3,500 figure assumes the loss is entirely fat and that your metabolism does not adapt. Neither holds exactly: some loss is lean tissue and water, and energy expenditure falls as body mass falls, so the same deficit produces less loss over time. Real results generally track a little behind the arithmetic, which is normal rather than a sign anything is wrong.
The calculator flags any target that falls below 1,200 calories for women or 1,500 for men. Those are commonly cited floors for self-directed dieting, and a smaller body may hit them at a 500-calorie deficit. If yours does, use the smaller deficit or speak to a clinician rather than eating less.
Age, and what actually changes
| Age | BMR | Maintenance |
|---|---|---|
| 20 | 1,787 | 2,458 |
| 30 | 1,737 | 2,389 |
| 40 | 1,687 | 2,320 |
| 50 | 1,637 | 2,251 |
| 60 | 1,587 | 2,183 |
| 70 | 1,537 | 2,114 |
The formula subtracts 5 calories per year of age, so fifty years costs about 344 calories a day at this weight — noticeable, but considerably less than the folk belief that metabolism collapses in middle age. Much of the real-world change comes from lost muscle and reduced daily movement rather than age itself, and both are more modifiable than a birthday.
Treat the number as a hypothesis
Mifflin-St Jeor estimates a population average, and individual expenditure can differ by several hundred calories in either direction at the same height, weight, age and sex. The formula also cannot see body composition: two people of identical stats with very different muscle mass will get identical estimates and burn differently.
- Use the number for two to three weeks, then judge by the weight trend rather than the estimate.
- Weigh at the same time daily and average across the week. Day-to-day swings are water and food volume, not fat.
- If nothing is moving on a deficit, the usual explanation is that intake is under-counted or activity over-counted, not that your metabolism is unusual.
- Recalculate as your weight changes. A lighter body burns less, so a target set 20 lb ago is no longer a deficit.
Once you have a calorie target, the macro calculator splits it into protein, carbohydrate and fat.
How this tdee calculator works out its numbers
BMR uses Mifflin-St Jeor: 10 × weight (kg) + 6.25 × height (cm) − 5 × age, plus 5 for men or minus 161 for women. TDEE is BMR multiplied by an activity factor.
- Activity factors are the standard set: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active, 1.9 athlete. This input dominates the result and is the most common source of error.
- Deficit and surplus targets use the 3,500-calories-per-pound convention. That assumes loss is entirely fat and that expenditure does not adapt, so actual results typically run behind the projection.
- A low-intake note appears when a 500-calorie deficit falls below 1,200 calories for women or 1,500 for men. These are widely cited floors for unsupervised dieting, not clinical thresholds.
- Population averages. Individual expenditure varies by several hundred calories at identical height, weight, age and sex, and the equation cannot see body composition or medical conditions affecting metabolism.
- Not medical advice. This is a starting estimate to test against real results over several weeks, not a prescription.
Reviewed September 2026.
Figures reviewed . Every worked example on this page is checked against the calculator above.
TDEE Calculator: frequently asked questions
What is the difference between BMR and TDEE?
BMR is what you burn at complete rest. TDEE multiplies it by an activity factor to include movement, exercise and digestion. For a 30-year-old man at 5'10" and 170 lb, BMR is about 1,737 and lightly active TDEE about 2,389.
How many calories to lose a pound a week?
About a 500-calorie daily deficit, since a pound of fat stores roughly 3,500 calories. That figure assumes all loss is fat and no metabolic adaptation, so real results usually run slightly behind it.
What activity level should I pick?
Lower than you think. A desk job with three gym sessions a week is lightly active, not very active. The gap between sedentary and athlete is over 1,200 calories a day, so one level too high can erase a deficit entirely.
Which BMR formula is most accurate?
Mifflin-St Jeor is the one most commonly recommended for general use and is what this calculator uses. Harris-Benedict is older and tends to read slightly higher. Neither accounts for body composition.
Is it safe to eat 1,200 calories a day?
1,200 for women and 1,500 for men are commonly cited floors for self-directed dieting. If a 500-calorie deficit takes your target below those, use a smaller deficit instead of eating less, and speak to a clinician.
Does metabolism really slow with age?
The formula subtracts 5 calories per year, so fifty years is about 344 calories a day at a typical weight — real but smaller than commonly believed. Much of the observed change comes from lost muscle and reduced movement rather than age itself.
Why am I not losing weight in a calorie deficit?
Usually the deficit is smaller than it appears: activity over-estimated, portions under-counted, or the target set at a heavier weight than you are now. Track carefully for two weeks and judge by the weekly average, not daily readings.
Should I recalculate my TDEE as I lose weight?
Yes. A lighter body burns fewer calories, so a target set 20 lb ago may no longer be a deficit. Recalculating every 10 to 15 lb keeps the estimate roughly current.