Your details
Include movement at work and at home, not only workouts. Results update as you type.
Your estimated total daily energy expenditure (TDEE).
- Resting energy (RMR)
- 1,650 kcal/day
- Activity multiplier
- ×1.55
A starting estimate, not a measured calorie requirement. Actual needs vary.
Compare daily calorie scenarios
These percentage adjustments illustrate a deficit or surplus. They do not predict a guaranteed rate of weight change.
| Scenario | Calculation | kcal/day |
|---|---|---|
| Weight-loss comparison | TDEE × 0.85 | 2,170 |
| Maintain weight | TDEE × 1.00 | 2,560 |
| Weight-gain comparison | TDEE × 1.10 | 2,810 |
Illustrative intake scenarios, not personalized nutrition prescriptions. Bar lengths start at zero; values are kcal/day.
How activity changes your estimate
This graph holds your age, sex, height and weight constant. Only the activity multiplier changes. The outlined point marks your selected level.
| Level | Multiplier | Typical pattern | kcal/day |
|---|---|---|---|
| Sedentary | 1.20 | Mostly seated, little planned exercise | 1,980 |
| Light | 1.375 | Some daily walking and light exercise | 2,270 |
| Moderate | 1.55 | Regular exercise plus daily movement | 2,560 |
| Very active | 1.725 | Substantial daily movement and frequent hard exercise | 2,840 |
| Extra active | 1.90 | Highly demanding physical work or training | 3,130 |
These are approximate calculator presets, not coefficients from the original Mifflin–St Jeor study. Sessions per week alone cannot determine your total activity.
How the calorie calculation works
The calculator estimates energy used at rest, then multiplies it by an activity factor to estimate maintenance calories. A food “Calorie” is a kilocalorie (kcal); all results here are kcal per day.
1. Estimate resting energy
The Mifflin–St Jeor equation uses weight, height, age and a sex-specific constant. It predicts resting energy expenditure (REE, also called RMR). BMR is measured under stricter conditions; this is an equation-based resting estimate.
RMR = 10 × W + 6.25 × H − 5 × A + 5
RMR = 10 × W + 6.25 × H − 5 × A − 161
W is weight in kilograms, H is height in centimeters, and A is age in years. For US inputs: kg = lb × 0.45359237; cm = (feet × 12 + inches) × 2.54.
2. Account for activity
TDEE = RMR × activity multiplier
Select the pattern that best describes your whole day. A desk job with three workouts is different from a physical job with the same workouts. The multiplier is intended to account broadly for daily energy expenditure beyond rest; do not add exercise calories again to the displayed result.
3. Compare a deficit and surplus
This page displays a 15% reduction and a 10% increase from estimated maintenance. These are transparent comparison settings, not individually prescribed targets. The calculator rounds only the final displayed values.
| Step | Arithmetic | Result |
|---|---|---|
| Resting energy | 700 + 1,093.75 − 150 + 5 | 1,648.75 kcal/day |
| Maintenance | 1,648.75 × 1.55 | ≈2,560 kcal/day |
| 15% deficit | 2,555.5625 × 0.85 | ≈2,170 kcal/day |
| 10% surplus | 2,555.5625 × 1.10 | ≈2,810 kcal/day |
What the result can and cannot tell you
Maintenance calories are an estimate of the intake that would balance your current daily expenditure. The equation does not measure your metabolism or body composition. Activity selection can change the result substantially, as the graph shows.
A calorie deficit does not translate into the same weight change every week. Energy expenditure changes with body weight and adaptation; short-term scale changes also include water. This calculator does not use a fixed calories-per-kilogram rule to promise a weight-loss date.
Use the result as a starting estimate and compare it with your intake and weight trend over several weeks. Recalculate when weight or activity changes. A sustained mismatch is a reason to review the inputs and the activity assumption.
Who this calculator is for
For adults aged 18–100, with supported heights of 100–250 cm and weights of 30–350 kg. These are input limits, not healthy ranges. It is not designed for children, pregnancy or breastfeeding. Medical conditions, recovery from illness and unusual body composition may require an individualized assessment.
Deficit scenarios are hidden for an adult BMI below 18.5 or an estimate below 1,000 kcal/day. This display safeguard does not establish a safe intake for everyone above those limits. Discuss individual nutrition needs with a qualified clinician or dietitian.
Sources: Mifflin et al., 1990 — resting energy equation; NIDDK — Body Weight Planner. This calculator uses a simple activity-factor estimate, not the NIDDK dynamic model.