Start with an estimate, not a rule
There is no single calorie number that fits everyone. Energy needs are estimated in steps: first your basal metabolic rate (BMR), the energy your body uses at rest, then a multiplier for your daily activity. The result is your total daily energy expenditure (TDEE) — an estimate of how many calories keep your weight stable.
We use the Mifflin-St Jeor equation for BMR because it is one of the most accurate formulas for healthy adults in validation studies. Even so, any equation can be off by 10% or more for a given person, so treat the result as a starting point.
Adjust the estimate for your goal
Once you know your maintenance calories, the goal decides the adjustment:
- Lose weight: eat roughly 15–25% below maintenance. Larger deficits are harder to sustain and increase muscle loss.
- Maintain: eat around maintenance.
- Build muscle: a small surplus of about 5–15% supports muscle gain while limiting fat gain.
- Never go below a safe floor (we use 1,200 kcal for women and 1,500 kcal for men, and never below your estimated BMR) without medical supervision.
Check your number with real data
Weigh yourself under similar conditions 3–4 times per week and compare weekly averages. If your weight is stable after two to three weeks at your 'maintenance' intake, the estimate was right. If you gain or lose unexpectedly, adjust by 100–200 kcal and reassess.
Daily weight fluctuates by 1–2 kg due to water, salt and food volume, so single weigh-ins are not meaningful.
Calories are only part of the picture
Food quality, protein intake, fibre and sleep influence hunger, energy and body composition. Once your calorie target is set, split it into macronutrients and build meals around mostly minimally processed foods.
Frequently asked questions
Is 2,000 calories a day right for me?
2,000 kcal is a reference value used on food labels, not a personal recommendation. Your needs may be higher or lower depending on size, age, sex and activity — use the calculator to estimate yours.
Should I eat back the calories I burn exercising?
Our activity factor already includes your usual exercise. Adding tracker estimates on top usually double-counts, because wearables tend to overestimate energy expenditure.
How fast should I lose weight?
A rate of about 0.5–1% of body weight per week is a common, sustainable target for most adults.
Sources
- 1Mifflin MD et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr, 1990.
- 2Hall KD et al. Quantification of the effect of energy imbalance on bodyweight. The Lancet, 2011.
- 3U.S. Department of Agriculture & HHS. Dietary Guidelines for Americans, 2020–2025.
