Calorie Calculator
This calorie calculator turns a weight goal into a daily eating target. It estimates the calories you need to maintain your current weight, then subtracts or adds enough for the weekly pace you choose, from losing 2 lb to gaining 1 lb a week. A table puts every goal side by side, and a built-in minimum stops weight-loss targets from dropping too low.
Updated
Results
- Maintenance calories (kcal/day)Estimated intake that keeps your weight stable
- BMR (kcal/day)Calories burned at complete rest
- Difference from maintenance (kcal/day)Negative = deficit, positive = surplus
- Planned change per week
- Calorie floorMinimum of 1,200 kcal (women) or 1,500 kcal (men)
| Change per week (lb or kg) | Calories per day (kcal) |
|---|
Results are estimates. See the methodology below.
How to use the calorie calculator
- Keep US units (pounds, feet and inches) or switch to metric.
- Choose your sex and enter your age (18 or older), weight and height.
- Pick the activity level of a typical week, counting your job as well as workouts. If unsure, take the lower one.
- Choose a goal: lose 0.5, 1, 1.5 or 2 lb a week, maintain, or gain 0.5 or 1 lb a week.
- Read your daily calorie target, your maintenance calories and the difference between them. The table compares the target for every goal.
How the calorie target is calculated
1. Maintenance calories
First the calculator estimates your basal metabolic rate (BMR) with the Mifflin-St Jeor equation (1990), after converting pounds and inches to kg and cm:
BMR = 10 × weight + 6.25 × height − 5 × age + 5 for men, or − 161 for women.
BMR is multiplied by an activity factor: 1.2 (sedentary), 1.375 (lightly active), 1.55 (moderately active), 1.725 (very active) or 1.9 (extremely active). The result is your estimated maintenance intake.
2. From weekly goal to daily difference
The calculator uses the common approximation that a pound of body weight equals about 3,500 kcal. Daily difference = weekly change × 3,500 ÷ 7:
| Goal | Difference per day |
|---|---|
| Lose 2 lb a week | −1,000 kcal |
| Lose 1.5 lb a week | −750 kcal |
| Lose 1 lb a week | −500 kcal |
| Lose 0.5 lb a week | −250 kcal |
| Gain 0.5 lb a week | +250 kcal |
| Gain 1 lb a week | +500 kcal |
In metric the options mean 1, 0.75, 0.5 and 0.25 kg a week at 7,700 kcal per kg (0.5 kg = 550 kcal a day), so the two systems differ slightly.
3. Minimum intake
A weight-loss target never goes below 1,200 kcal a day for women or 1,500 kcal for men. This floor is built into the calculator; it is not a personal recommendation. When it applies, the Calorie floor result says so, and your real deficit is smaller than the goal implies.
Examples
Woman, 35, 5 ft 5 in, 165 lb, lightly active, lose 1 lb a week
BMR 1,444 kcal, maintenance 1,986 kcal. Target: 1,486 kcal a day, 500 below maintenance. The slower 0.5 lb pace would allow 1,736 kcal.
The same woman, 20 lb later
At 145 lb her maintenance drops to 1,861 kcal and the 1 lb target to 1,361 kcal. Staying at 1,486 kcal would now be only 375 kcal below maintenance, one reason progress slows over time.
Man, 45, 5 ft 10 in, 210 lb, moderately active, lose 2 lb a week
Maintenance 2,858 kcal, target 1,858 kcal (−1,000); 1 lb a week would be 2,358 kcal.
Woman, 60, 5 ft 2 in, 130 lb, sedentary, lose 1.5 lb a week
Maintenance is just 1,336 kcal. Subtracting 750 would fall far below the minimum, so the target is set to 1,200 kcal: a real deficit of only 136 kcal a day.
How to read your target
The 3,500-calorie rule is a simplification. Researchers who tested it against measured weight loss found that it grossly overestimates how much people lose over time, and they recommend dynamic models instead. The NIH Body Weight Planner is one such free tool.
According to the CDC, people who lose weight gradually and steadily, about 1 to 2 lb a week, are more likely to keep it off, and even a modest loss can improve blood pressure, cholesterol and blood sugar.
Do not use this calculator if you are pregnant or breastfeeding, under 18, or have or have had an eating disorder. With a medical condition or medication that affects weight, talk to your doctor or a registered dietitian first.
Frequently asked questions
How many calories should I eat a day to lose weight?
There is no single number. The calculator subtracts 250 to 1,000 kcal from your estimated maintenance, depending on your goal. Treat it as a starting point: follow your weight for two to four weeks and adjust by 100 to 200 kcal.
Is 1,200 calories a day enough?
1,200 kcal is the lowest weight-loss target this calculator shows for women (1,500 for men), not a goal in itself. Many adults need much more. Eating that little makes it hard to get enough nutrients, so check with a doctor or registered dietitian first.
Why am I losing more slowly than the calculator predicts?
Formulas describe averages, and your maintenance may be lower than estimated. As you lose weight you burn less, so a fixed intake gives a shrinking deficit, and water shifts can hide fat loss for a week or two.
How is this different from a BMR or TDEE calculator?
BMR is the energy your body uses at rest; TDEE is your maintenance intake including activity. This calculator goes one step further: it converts a weekly weight goal into a daily intake and compares all goals at once.
Should I add the calories I burn exercising?
Usually not. Your activity level already includes your normal workouts, so adding calories from a fitness tracker on top would count them twice.
Sources
- Mifflin MD, St Jeor ST, et al. — A new predictive equation for resting energy expenditure in healthy individuals (Am J Clin Nutr, 1990)
- Thomas DM, Martin CK, et al. — Can a weight loss of one pound a week be achieved with a 3500-kcal deficit? (Int J Obes, 2013)
- NIDDK (National Institutes of Health) — Body Weight Planner
- CDC — Steps for Losing Weight
- USDA & HHS — Dietary Guidelines for Americans
This calculator gives general estimates and is not medical or nutrition advice. It is not intended for pregnancy, breastfeeding, people under 18, eating disorders or medical conditions; talk to a doctor or registered dietitian.