TDEE Calculator

What Is TDEE?

TDEE (Total Daily Energy Expenditure) is the estimated total number of calories your body uses in an average day. It includes resting energy expenditure, exercise, everyday movement, and the energy required to digest food.

Your TDEE is commonly used as an estimate of your maintenance calories: the daily energy intake that may maintain your current body weight when averaged over time.

Because daily movement and other factors change, your actual energy expenditure is not identical every day.

How to Calculate TDEE: Formula and Method

RepMaths first estimates resting energy expenditure using the Mifflin-St Jeor equation, then applies your selected activity multiplier.

Male equation

BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5

Female equation

BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

TDEE formula

TDEE = Estimated BMR × Activity Multiplier

The calculator labels the equation result as BMR for familiarity. More precisely, Mifflin-St Jeor predicts resting energy expenditure; this is not a direct laboratory measurement of basal metabolic rate.

You can also use the dedicated BMR Calculator to explore resting calorie needs separately.

TDEE Calculation Example

Consider a 30-year-old man weighing 80 kg and measuring 180 cm, with a moderately active lifestyle.

The calculation is 1,780 × 1.55 = 2,759 kcal/day. This is an initial maintenance estimate, not a guarantee that eating exactly 2,759 calories will maintain weight.

TDEE Activity Level Multipliers Explained

These multipliers are broad planning estimates rather than precise measurements. A person who lifts weights four days per week but otherwise sits for most of the day may have a lower overall activity level than expected.

When unsure, select a conservative activity level and refine your maintenance estimate using your actual weight trend.

How Many Calories Do I Need to Maintain My Weight?

Your estimated maintenance calories are the central result of this TDEE calculator. They represent an initial estimate of how much energy you may need each day to maintain your current weight.

To improve accuracy, compare your average calorie intake with your average body-weight trend over several weeks. Daily fluctuations caused by water, sodium, digestion, and glycogen can obscure shorter-term changes.

Using TDEE for Weight Loss and Cutting

A calorie deficit occurs when average calorie intake is lower than energy expenditure. This calculator displays illustrative targets 300 and 500 calories below estimated maintenance.

These adjustments are not suitable for everyone. Appropriate energy intake depends on individual health, body size, activity, training demands, and other circumstances.

For a more focused starting estimate, visit the Calorie Deficit Calculator . For nutritional planning during a cut, use the Protein Calculator.

Using TDEE for Muscle Gain and Bulking

When aiming to gain muscle, estimated TDEE can provide a maintenance reference. A modest calorie surplus is commonly used alongside progressive resistance training and sufficient dietary protein.

The calculator displays illustrative additions of 250 and 400 calories per day. The appropriate surplus depends on your training experience, goals, and observed progress.

Use our Macro Calculator to explore daily protein, carbohydrate, and fat targets.

How Accurate Is a TDEE Calculator?

TDEE calculators provide predictions, not direct measurements. Two important sources of uncertainty are the resting-energy equation and the selected activity multiplier.

The Mifflin-St Jeor equation is widely used, but even a well-performing population-level equation can overestimate or underestimate an individual's actual energy needs.

How to refine your maintenance estimate

1. Calculate your initial TDEE.
2. Track food intake consistently for several weeks.
3. Compare average body weight across those weeks.
4. Review changes in training and daily activity.
5. Adjust your calorie estimate gradually if needed.

This feedback-based approach is generally more useful than assuming a formula produces a permanently exact calorie target.

Mifflin-St Jeor vs. Harris-Benedict

Mifflin-St Jeor and Harris-Benedict are predictive equations used to estimate resting energy expenditure. They use variables such as age, weight, height, and sex, but their coefficients differ.

RepMaths uses Mifflin-St Jeor because it is a well-established option for estimating adult resting energy expenditure. No predictive equation is universally accurate for every individual or population.

BMR vs. TDEE: What's the Difference?

BMR represents estimated energy requirements under basal resting conditions. TDEE extends that starting point to account for overall daily energy expenditure.

If your goal is to estimate everyday maintenance calories, TDEE is generally the more relevant planning figure. BMR should not be confused with a personalized minimum calorie-intake recommendation.

Frequently Asked Questions

Sources and Further Reading

The following references provide background on resting energy prediction and weight-management methodology. The activity factors and goal adjustments displayed by RepMaths remain estimates rather than clinical prescriptions.

• Mifflin et al. (1990) — A New Predictive Equation for Resting Energy Expenditure
• Frankenfield et al. (2005) — Comparison of Predictive Equations for Resting Metabolic Rate
• NIDDK — Weight Management Information