A TDEE calculator estimates how many calories you may need to maintain your current weight based on your resting metabolism and usual activity. This guide explains how the estimate works, how to choose a reasonable calorie deficit, what the numbers cannot tell you, and when to recalculate as your body, routine, or goals change.
Overview
Total daily energy expenditure (TDEE) is an estimate of the energy your body uses in a typical day. It includes energy needed for basic body functions, movement and exercise, digestion, and other daily activity. A maintenance calorie calculator uses your personal details to estimate this total.
TDEE is not a laboratory measurement or a guaranteed calorie prescription. Two people with the same height, weight, age, and activity description can have different energy needs. Use the result as a starting point, then compare it with weight trends, hunger, energy, exercise performance, and other signs over several weeks.
A TDEE estimate can be useful for several goals:
- Estimating daily calorie needs for weight maintenance
- Creating a moderate calorie deficit for gradual weight loss
- Setting an initial calorie target before adjusting based on real-world results
- Understanding why calorie needs may change after weight loss or a major activity change
For a broader picture of health, pair calorie estimates with other measures rather than relying on body weight alone. A waist-to-height ratio calculator may add context about body-size distribution, while a one-rep max calculator can help track strength-related goals.
How to estimate
Most TDEE calculators use two steps. First, they estimate your basal metabolic rate (BMR), or the energy your body may use at rest. One commonly used approach is the Mifflin–St Jeor equation:
- For males: BMR = (10 × weight in kilograms) + (6.25 × height in centimeters) − (5 × age) + 5
- For females: BMR = (10 × weight in kilograms) + (6.25 × height in centimeters) − (5 × age) − 161
These equations use sex categories because the original calculation includes a sex-based constant. They do not capture every aspect of sex, gender, body composition, hormonal status, or individual metabolism. If the available categories do not describe you, treat the result as a rough range and consider discussing personalized nutrition targets with a qualified clinician or registered dietitian.
Second, the BMR estimate is multiplied by an activity factor. The following categories are practical starting points:
- Sedentary: little planned exercise and mostly sitting during the day; factor about 1.2
- Lightly active: regular light movement or light exercise one to three days per week; factor about 1.35
- Moderately active: purposeful exercise or an active routine several days per week; factor about 1.5
- Very active: hard training or physically demanding work on many days; factor about 1.7
- Exceptionally active: very high training volume combined with a physically demanding lifestyle; use cautiously and consider professional guidance
TDEE is then estimated as:
TDEE = BMR × activity factor
To estimate a calorie deficit, subtract a modest percentage from estimated maintenance calories. A practical starting point is often about 10% to 20%, depending on the person, goal, current intake, and ability to maintain the plan. For example, someone with an estimated TDEE of 2,400 calories might begin around 2,160 calories at a 10% reduction or 1,920 calories at a 20% reduction. This is an estimate, not a requirement to eat a specific number.
TDEE calculator
Enter your details for an estimate. Use kilograms and centimeters, or convert your measurements before entering them.
Your result will appear here.
Inputs and assumptions
The quality of a TDEE estimate depends on the quality of the inputs. Weigh yourself under consistent conditions, use a reasonably accurate height measurement, and choose activity based on your whole routine rather than your hardest workout.
Activity factors are especially uncertain. A person who exercises three times per week but sits for most of the day may not fit the same category as someone who walks frequently and has an active job. If you are unsure, choose the lower reasonable category and adjust after observing your trend.
Exercise calories should not automatically be added back one-for-one. Fitness trackers and exercise machines can overestimate energy expenditure, and the activity factor may already include some movement. Pick one consistent method, record your intake and weight trend, and avoid changing several variables at once.
A calorie target also needs to support nutrition quality. Include adequate protein and fiber, vegetables and fruit, sources of unsaturated fat, and enough fluids. A calculator does not assess micronutrient needs, medical conditions, medication effects, sleep, stress, or the relationship someone has with food.
Do not use a generic deficit target without professional advice if you are pregnant or breastfeeding, under 18, recovering from an eating disorder, underweight, dealing with unintended weight loss, or managing diabetes, kidney disease, gastrointestinal disease, or another condition that affects nutrition. A clinician or dietitian can help set a safer plan.
Worked examples
Example 1: estimating maintenance calories
Suppose a 30-year-old male weighs 70 kg, is 175 cm tall, and selects a moderately active factor of 1.5. His estimated BMR is approximately 1,680 calories per day. Multiplying by 1.5 gives an estimated TDEE of about 2,520 calories per day. That number is a starting estimate for maintenance, not a promise that weight will remain identical each day.
Example 2: choosing a moderate deficit
For the same person, a 10% to 20% reduction would produce a starting range of roughly 2,270 to 2,020 calories per day. Starting nearer the smaller reduction may be more comfortable for someone who is active, hungry, or trying to preserve training performance. The appropriate target depends on the individual and should be adjusted using results.
Example 3: why trends matter
Daily weight can move because of fluid, sodium, carbohydrate intake, digestion, menstrual-cycle changes, and training-related inflammation. Instead of reacting to one reading, weigh under similar conditions and review a multi-week trend. If the trend is stable and the goal is fat loss, the actual maintenance level may be close to the current average intake, regardless of what the calculator predicted.
When to recalculate
Revisit your TDEE estimate when a meaningful input changes, not every time the scale fluctuates. Recalculate after losing or gaining a noticeable amount of weight, changing your training schedule, starting or ending a physically active job, or experiencing a sustained change in daily movement.
Use this adjustment checklist:
- Record your starting weight, estimated calorie intake, activity routine, and goal.
- Keep the plan reasonably consistent for several weeks unless you feel unwell or the approach is clearly unsuitable.
- Review the average weight trend, hunger, energy, recovery, sleep, and exercise performance.
- If progress is slower than intended, first check portion estimates, drinks, snacks, weekend intake, and activity assumptions.
- Make a small adjustment rather than pursuing an aggressive restriction. Recalculate after a substantial body-weight or activity change.
- Stop and seek professional advice if you develop dizziness, fainting, persistent fatigue, bingeing, purging, rapid unintended weight loss, or other concerning symptoms.
The most useful TDEE calculator is one you return to thoughtfully. Treat its result as a planning tool, combine it with real-world feedback, and prioritize a sustainable eating pattern over precision that the calculator cannot provide.
