How to Calculate Your Maintenance Calories — TDEE Guide

Blog › Health · 8 min read · Published 2026-03-07

Learn how to calculate maintenance calories using the Mifflin-St Jeor equation, activity multipliers, and practical tips for weight management.

What Are Maintenance Calories?

Maintenance calories, also known as Total Daily Energy Expenditure (TDEE), represent the number of calories your body burns in a day to maintain its current weight. This includes all energy used for basic bodily functions (breathing, digestion, cell repair), physical activity, and the thermic effect of food.

Understanding your maintenance calories is the foundation of any weight management strategy. Eating above maintenance leads to weight gain, eating below leads to weight loss, and eating at maintenance keeps your weight stable.

The Mifflin-St Jeor Equation

The most accurate clinically-validated formula for estimating Basal Metabolic Rate (BMR) is the Mifflin-St Jeor equation, published in 1990. It outperforms the older Harris-Benedict equation by about 5% accuracy.

For men: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(years) + 5

For women: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(years) - 161

BMR represents the calories your body needs at complete rest — just to keep your organs functioning, your heart beating, and your lungs breathing. It accounts for roughly 60-75% of total daily energy expenditure.

Activity Multipliers

To convert BMR to TDEE, multiply by an activity factor that accounts for your daily movement and exercise habits:

Sedentary (×1.2): Desk job, little to no exercise. This describes most office workers who don't have a regular exercise routine.
Lightly active (×1.375): Light exercise 1-3 days per week. This includes casual walking, light yoga, or recreational sports once or twice weekly.
Moderately active (×1.55): Moderate exercise 3-5 days per week. Regular gym sessions, jogging, cycling, or structured workout programs.
Very active (×1.725): Hard exercise 6-7 days per week. Serious athletes, daily intense training sessions, or physically demanding occupations.
Extra active (×1.9): Very hard exercise plus a physical job. Professional athletes, military training, or construction workers who also exercise.

Most people overestimate their activity level. If you're unsure, choose one level lower than you think. A common mistake is selecting "moderately active" when "lightly active" is more accurate.

Components of TDEE

Your total daily energy expenditure is made up of four components:

1. Basal Metabolic Rate (BMR): 60-75% of TDEE. The energy your body needs to sustain basic life functions. This is influenced by muscle mass, age, genetics, and hormonal status.

2. Thermic Effect of Food (TEF): 8-15% of TDEE. The energy required to digest, absorb, and process nutrients. Protein has the highest TEF (20-30%), followed by carbs (5-10%), then fats (0-3%).

3. Exercise Activity Thermogenesis (EAT): 5-10% of TDEE for most people. Planned exercise and structured workouts. This is the component most people focus on, but it's typically the smallest.

4. Non-Exercise Activity Thermogenesis (NEAT): 15-30% of TDEE. All movement that isn't planned exercise: walking, fidgeting, standing, household chores. NEAT is the most variable component and can differ by up to 2,000 calories between individuals.

Using Maintenance Calories for Weight Management

Once you know your TDEE, you can create strategic calorie targets:

Fat loss: Eat 250-500 calories below TDEE for 0.25-0.5 kg (0.5-1 lb) loss per week. Aggressive deficits beyond 750 calories increase muscle loss risk.
Muscle gain: Eat 250-500 calories above TDEE with adequate protein (1.6-2.2g/kg) and resistance training.
Body recomposition: Eat at or slightly below TDEE with high protein and progressive overload. Slower but simultaneous fat loss and muscle gain.

Metabolic Adaptation

During prolonged calorie restriction, your body adapts by reducing TDEE through several mechanisms: decreased NEAT (you move less unconsciously), reduced thyroid hormone output, lower leptin levels, and increased metabolic efficiency. This is why weight loss plateaus occur.

Strategies to manage adaptation include diet breaks (eating at maintenance for 1-2 weeks every 8-12 weeks), refeed days (1-2 days at maintenance, focused on carbohydrates), and reverse dieting (gradually increasing calories after a diet phase).

Practical Tips

Track your food intake and weight for 2-3 weeks to find your actual maintenance calories empirically. If your weight is stable, your average intake equals your TDEE. Adjust the calculated estimate based on real-world results. Use a maintenance calories calculator as a starting point, then fine-tune based on your body's response.

FAQ

How often should I recalculate maintenance calories?

Every 4-8 weeks during active weight change, or whenever your weight shifts by more than 5 kg. Age, muscle mass changes, and lifestyle shifts all warrant recalculation.

Are online calculators accurate?

They're a good starting point (±10% for most people). Individual variation exists due to genetics, body composition, and metabolic health. Use calculated values as estimates and adjust based on real results.