Introduction
Knowing how many calories you need to maintain your weight is the foundation of almost every nutrition goal. Whether you want to lose fat, gain muscle, or simply stop guessing at portion sizes, you need a solid estimate of your Total Daily Energy Expenditure—your TDEE. This guide walks you through what TDEE is, how to calculate it (including a free method you can use right now), and how to use that number for fat loss, muscle gain, or maintenance.
You don’t need a lab test or a paid calculator. The same formulas that apps and online TDEE calculators use can be applied with a piece of paper or a spreadsheet, and we’ll show you how. Then we’ll cover how to turn that maintenance number into a practical daily target.
What Is TDEE?
TDEE stands for Total Daily Energy Expenditure. It’s the total number of calories your body burns in a typical day. That includes the energy you burn at rest (your basal metabolic rate, or BMR), the energy used to digest and process food (thermic effect of food), and the energy you spend moving—everything from walking and exercise to fidgeting and standing.
When you eat the same number of calories as your TDEE, your weight tends to stay stable; that’s why TDEE is often called your maintenance calories. Eat consistently below TDEE and you lose weight; eat consistently above it and you gain. So getting a reasonable estimate of TDEE is the first step before you set a deficit for fat loss or a surplus for muscle gain.
How TDEE Is Estimated
Scientists and apps estimate TDEE in two steps. First they estimate your BMR—the calories you’d burn if you did nothing all day—using equations based on age, sex, height, and weight. The most common one is the Mifflin-St Jeor equation. Second, they multiply BMR by an activity factor that represents how active you are. That product is your TDEE.
The activity factor is where a lot of the variation comes in. People often over- or underestimate how active they are. A good approach is to start with a moderate factor (e.g. 1.4–1.55), use the resulting TDEE as your starting maintenance, and then adjust based on real-world results over two to four weeks.
Activity Factors: What Multiplier to Use
Below is a common set of activity factors used by TDEE calculators. Pick the one that best matches your typical week, not your best week.
| Activity level | Multiplier | Typical description |
|---|---|---|
| Sedentary | 1.2 | Little or no exercise, desk job |
| Lightly active | 1.375 | Light exercise 1–3 days/week |
| Moderately active | 1.55 | Moderate exercise 3–5 days/week |
| Very active | 1.725 | Hard exercise 6–7 days/week |
| Extremely active | 1.9 | Very hard exercise, physical job |
If you’re unsure, choose the next level down rather than up. You can always add calories later if you’re losing weight too fast or feeling run-down.
Using Your TDEE for Fat Loss, Gain, or Maintenance
Once you have a TDEE estimate, you use it to set a daily calorie target. For maintenance, that target is your TDEE. For fat loss, you subtract a sensible deficit (often 300–500 calories); for muscle gain, you add a small surplus (often 200–300 calories). The table below summarizes how to use your TDEE for each goal.
| Goal | Daily intake vs TDEE | Rough outcome |
|---|---|---|
| Maintenance | At TDEE | Weight stable |
| Fat loss | 200–500 cal below TDEE | ~0.5–1 lb loss per week |
| Muscle gain | 200–300 cal above TDEE | Slow, lean gain |
Revisit your TDEE every few weeks or after a noticeable weight change. As you lose weight, your TDEE drops, so your deficit shrinks unless you lower intake a bit. As you gain weight, TDEE goes up. Updating your target keeps your results on track.
Getting Your Number and Tracking It
You can plug your stats into any TDEE calculator that uses Mifflin-St Jeor and the activity factors above, or use an app that does it for you. SpotWell, for example, asks for your age, sex, height, weight, activity level, and goal, then calculates TDEE and suggests a calorie (and macro) target. You don’t have to do the math yourself.
After you have a target, the next step is to track intake for a while. If you’re maintaining and your weight is stable, you’ve found your maintenance. If you’re trying to lose or gain, track consistently and adjust based on scale and how you feel. For a step-by-step approach to setting a deficit, see our calorie deficit calculator guide. To track calories and macros without the hassle of manual entry, try SpotWell’s AI meal logging.