Daily Calorie Calculator: How Many Calories Should I Eat?

How many calories should I eat a day?

Most adults maintain their weight on roughly 1,600–2,400 calories (women) or 2,000–3,000 calories (men), depending on age and activity — that is the range in the Dietary Guidelines for Americans (2020–2025 edition). Your personal number sits somewhere inside it. The calculator narrows it down with your body size and activity; treat the result as a starting point and adjust after two to three weeks of real-world weighing.

Maintenance calories explained

Maintenance calories = the energy you burn in a typical day, also called TDEE. It is your resting metabolism (about 60–70% of the total for most people) plus movement, exercise and the energy used to digest food. Eat at maintenance and your weight stays flat; eat below it and you lose; above it and you gain.

How many calories to lose weight

A deficit of about 500 calories a day below maintenance produces a gradual loss of roughly 0.5 kg (1 lb) per week — the pace the CDC links with keeping the weight off. Larger deficits work faster but cost muscle and are harder to sustain. The calorie deficit calculator sets this up for you and estimates your goal date.

Calories to gain weight

To gain muscle rather than fat, add a modest surplus — about 250–500 calories above maintenance — together with resistance training and enough protein. The calorie surplus calculator turns that into a daily target.

How this calorie calculator works

It estimates resting energy expenditure with the Mifflin-St Jeor equation (the most accurate of the common formulas for healthy adults in validation studies), multiplies it by an activity factor, and applies your goal. Because activity is self-reported, real needs can differ by 10–20%.

Sources

• Dietary Guidelines for Americans, 2020–2025 edition, Appendix 2 (estimated calorie needs); current edition — https://www.dietaryguidelines.gov/
• CDC, Losing weight (steady 1–2 lb/week) — https://www.cdc.gov/healthy-weight-growth/losing-weight/index.html
• Mifflin MD et al., Am J Clin Nutr 1990 (PubMed 2305711) — https://pubmed.ncbi.nlm.nih.gov/2305711/

This calculator is educational and not medical advice. If you have a health condition, are pregnant, or are under 18, ask a clinician before changing your diet.