Find the number of calories you burn per day — your maintenance level — plus targets for losing fat or building muscle, using the Mifflin-St Jeor equation.
What Are Maintenance Calories?
Your maintenance calories — also called Total Daily Energy Expenditure (TDEE) — are the number of calories you burn in a day. Eat that amount and your weight stays stable. Eat below it to lose fat, above it to gain weight. It's the foundation of any nutrition plan.
How TDEE Is Calculated
This calculator first finds your Basal Metabolic Rate (BMR) — calories burned at complete rest — using the Mifflin-St Jeor equation, the most accurate formula for most people. It then multiplies BMR by an activity factor (1.2 to 1.9) to account for movement and exercise, giving your maintenance calories.
Cutting and Bulking From Maintenance
To lose about one pound of fat per week, eat roughly 500 calories below maintenance. To build muscle with minimal fat gain, a smaller surplus of 200–400 calories works well. The results above show both targets so you can pick a direction without recalculating.
Why Your Real Burn May Differ
These formulas are population averages. Your true maintenance can vary by 5–10% based on genetics, muscle mass, and non-exercise movement. Treat the number as a starting estimate: track your weight for 2–3 weeks and adjust calories up or down based on what actually happens.
Tip: Don't cut calories too aggressively. A 500-calorie deficit is sustainable for most people; deeper cuts often backfire with muscle loss and rebound eating. Pair your target with the protein calculator to preserve lean mass.
Frequently Asked Questions
What are maintenance calories?
Maintenance calories are the number you can eat each day to keep your weight stable — your total daily energy expenditure. Eating below it leads to fat loss; above it leads to weight gain. This calculator estimates yours from your stats and activity.
How do I calculate my maintenance calories?
Calculate your BMR with the Mifflin-St Jeor formula, then multiply by an activity factor from 1.2 (sedentary) to 1.9 (very active). This tool does both automatically and also shows your BMR, fat-loss, and muscle-gain targets.
How many calories to lose weight?
To lose about one pound per week, eat roughly 500 calories below your maintenance level each day. The 'Fat Loss' figure above already applies that deficit. Combine the deficit with high protein and strength training to keep muscle.
Is the Mifflin-St Jeor formula accurate?
Mifflin-St Jeor is considered the most accurate calorie formula for the general population, typically within about 10% of true expenditure. Individual results vary with muscle mass and activity, so adjust based on real-world weight changes.
Why am I not losing weight in a deficit?
Common reasons include underestimating portions, overestimating activity, or water-weight fluctuations masking fat loss. Track intake honestly for two weeks; if weight truly holds, lower calories by 100–200 or add activity.