Your maintenance calories are the number that keeps your weight stable — the foundation of any diet plan. Here's how to find yours.
Your maintenance calories — also called Total Daily Energy Expenditure (TDEE) — are how many calories you burn in a day. Eat that amount and your weight holds steady. Eat below it and you lose fat; above it and you gain. Everything in a nutrition plan is built from this number.
First find your Basal Metabolic Rate (BMR) — calories burned at rest — using the Mifflin-St Jeor equation, the most accurate for most people. Then multiply BMR by an activity factor from 1.2 (sedentary) to 1.9 (very active) to get your maintenance calories.
A 30-year-old man, 180 lb and 5'10", has a BMR around 1,790. At a 'moderately active' factor of 1.55, his maintenance is about 2,775 calories a day. A lightly active person of the same stats would land closer to 2,460.
To lose about a 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. Pair either target with enough protein — see our protein guide.
These formulas are averages and can be off by 5–10% for any individual, depending on muscle mass and daily movement. Treat the number as a starting estimate: track your weight for two to three weeks and adjust up or down based on what actually happens.