How your target is calculated
The calculator first estimates your maintenance calories (TDEE), then applies the adjustment your goal implies — roughly 500 kcal/day per 0.5 kg of weekly change, based on the ~7,700 kcal energy content of a kilogram of body fat.
It also enforces a sensible floor (1,200 kcal/day for women, 1,500 for men). If your chosen rate would dip below that, the target is capped and flagged — very low intakes cost muscle, energy, and adherence, and deserve medical supervision, not a web calculator.
Making the number work
- Consistency beats precision. Hitting ±100 kcal of target daily outperforms nailing it Monday and ignoring it Saturday.
- Protein protects. In a deficit, high protein retains muscle — see the protein calculator.
- Re-run monthly. As your weight changes, your TDEE changes with it.
Frequently asked questions
How many calories should I eat to lose weight?
Most people lose steadily at 500 kcal/day below maintenance — roughly 0.5 kg (1 lb) per week. Smaller deficits are slower but easier to sustain and kinder to muscle.
Is 1,200 calories a day safe?
It's the commonly cited minimum for women (1,500 for men) below which meeting micronutrient needs gets difficult. Some people medically supervised go lower, but as a self-directed target it should be treated as a hard floor.
Why am I not losing weight on my calculated calories?
The estimate may simply run high for you, or intake is higher than logged — under-reporting of 20–40% is extremely common in studies. Drop 150–200 kcal or tighten tracking for two weeks before concluding anything.
Do I need to cycle calories or can I eat the same every day?
Either works — weekly average is what matters. See our guide to calorie cycling if varying high and low days fits your life better.
More calculators
TDEE Calculator
Work out your Total Daily Energy Expenditure
BMR Calculator
Estimate the calories your body burns at complete rest, compared across the three standard equations
Calorie Deficit Calculator
Choose a weekly weight-loss rate and see the exact daily calories that achieve it
Macro Calculator
Split your daily calories into protein, carbs and fat
Maintenance Calorie Calculator
Find the daily calories that keep your weight stable
Weight Loss Calculator
See your realistic goal date
Sources
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990. [link]
- Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011. [link]
- Wishnofsky M. Caloric equivalents of gained or lost weight. Am J Clin Nutr. 1958. [link]
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020–2025. [link]