Daily Calorie Calculator: How Many Calories Should I Eat?
Get your maintenance calories, plus targets for losing or gaining weight, from your age, sex, height, weight and activity level.
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.
What the result tells you
About what you'd eat to hold steady at your current weight, given how active you are. Your goal nudges it up or down from here.
How to use it
- New to tracking? Log your usual food for 3–4 days first and treat this as a ±100 kcal range.
- Judge progress from your weekly-average weight over 2–3 weeks, not day to day.
- Adjust 100–150 kcal at a time once a clear trend shows.
Recommendations
- Build meals around protein and plenty of plants, with a comfortable energy source.
- Weigh yourself under the same conditions a few mornings a week and average it.
- Recalculate after a meaningful change in weight, activity, or training.
Health & wellbeing
Feeling cold, drained, or preoccupied with food are signs to eat more, not less. This isn't built for pregnancy, breastfeeding, under-18s, or eating-disorder recovery.
Troubleshooting
Number looks off? Re-check height, weight, age, activity, and units. Don't use a target below about 1,200 kcal without medical supervision.
How it’s calculated
This uses the Mifflin–St Jeor equation for resting energy, then multiplies by an activity factor to estimate your total daily energy, and applies your goal.
Resting energy (kcal/day) = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 (men) or − 161 (women).
Daily target = resting energy × activity factor (1.2–1.9), adjusted for your goal.
Source: Mifflin MD, St Jeor ST, et al., American Journal of Clinical Nutrition, 1990.
Common questions
Is it safe to eat 1,200 calories a day?
For most adults that is below the level at which you can meet nutrient needs without supervision; the guidelines' lowest adult pattern is 1,600. Check with a clinician before going lower.
Why is my weight not changing at the calculated number?
Activity estimates are rough. Track intake for two weeks and adjust by 100–200 calories at a time.
Do I need to eat back exercise calories?
The activity level already includes typical training, so do not add them again.