How Many Calories Do You Need Each Day?
Your daily calorie requirement — often called Total Daily Energy Expenditure (TDEE) — is the total number of calories your body needs to maintain your current weight given your typical activity level. It combines your Basal Metabolic Rate (calories burned at rest) with the energy you use through movement, exercise, and digestion.
Use this calculator to find your maintenance calories, then adjust up or down depending on your goal. I designed it to give you three targets at once: maintenance, a moderate deficit for weight loss, and a moderate surplus for muscle gain — so you can choose the right number without doing extra maths.
Understanding Your Activity Multiplier
The activity multiplier is the single biggest variable in daily calorie calculations. Most people underestimate how active they actually are — or overestimate. Here is a guide to choosing the right level:
- Sedentary: desk job, little intentional exercise — multiply BMR by 1.2
- Lightly active: 1–3 days of exercise per week — multiply BMR by 1.375
- Moderately active: 3–5 days of exercise per week — multiply BMR by 1.55
- Very active: hard exercise 6–7 days per week — multiply BMR by 1.725
- Extra active: physical labour job or twice-daily training — multiply BMR by 1.9
If you are unsure, start with "lightly active" — it is better to start conservative and adjust based on real results than to overestimate and wonder why the scale is not moving.
Setting Calorie Targets for Your Goal
Once you know your maintenance calories, adjusting for your goal is straightforward. A deficit of 500 calories per day theoretically produces roughly 0.5 kg (1 lb) of fat loss per week, based on the assumption that 1 lb of fat contains approximately 3,500 calories. In practice, the body adapts, so results vary.
For muscle gain, a smaller surplus of 200–300 calories above maintenance is generally recommended. Large surpluses tend to add unnecessary fat rather than accelerating muscle growth, especially for natural lifters. Pair your calorie target with adequate protein intake — use the Protein Intake Calculator to find your target.
Frequently Asked Questions
Why is my calculated TDEE different from what my fitness tracker shows?
Formula-based calculations and wearable devices use different methods, and both have margins of error. Research suggests wearables can overestimate calorie burn by 20–40% depending on the device and activity type. Treat any calorie estimate — including this one — as a starting point. Track your weight for 2–3 weeks at your calculated target and adjust if results do not match expectations.
How often should I recalculate my daily calories?
Recalculate whenever your weight changes significantly (5+ kg), your activity level changes, or your results plateau for more than 3–4 weeks. As you lose weight, your maintenance calories decrease, so what produced a deficit at the start may become maintenance over time.
Is it bad to eat below my BMR?
Consistently eating below your BMR — the calories needed just to keep your organs functioning — is generally not recommended outside of medically supervised programmes. Very low calorie diets can cause muscle loss, nutrient deficiencies, and metabolic adaptation. This is an estimate — please consult a healthcare provider or registered dietitian before making significant changes to your diet.
