How the target is calculated
The calculator finds your basal metabolic rate with the Mifflin-St Jeor equation, then multiplies it by an activity factor to reach total daily energy expenditure. Weight change targets are built from the widely used figure of roughly 7,700 kcal per kilogram of body fat, which puts a 0.5 kg weekly loss at about 550 kcal a day below maintenance.
Choosing the right activity level honestly
This is where most people overestimate. A desk job with three gym sessions a week is "light to moderate", not "very active". Walking 12,000 steps and doing manual work is moderate. The athlete multiplier is for people training twice a day, not for people who train hard once. Overstating activity is the most common reason a calorie target fails to produce the expected result.
What to do when the number does not work
Every equation here is a prediction, and predictions carry error. Eat at the calculated maintenance figure for two to three weeks, weigh yourself at the same time on the same days, and take the trend rather than any single reading. If weight is stable, the estimate was right. If it drifts, adjust by 100 to 200 kcal and repeat.
Calories are not the only thing
Protein preserves muscle in a deficit and is the most satiating macronutrient — roughly 1.6 g per kilogram of body weight is a well-supported target for people who train. Fibre, sleep and resistance training all affect how a deficit feels and how much of the loss comes from fat rather than muscle. The BMR calculator shows the resting energy these targets are built on, and the BMI calculator helps set a broad weight range.
How many calories to lose weight
Weight loss comes from eating fewer calories than you burn, and the size of that gap sets the pace. A deficit of about 550 kcal a day produces roughly half a kilogram of loss per week, while 1,100 a day targets about a kilogram — though larger deficits get harder to sustain and risk muscle loss. There is no need to be extreme: a moderate deficit you can hold for months beats an aggressive one you abandon in weeks. Enter your details above and the calculator shows the intake for each pace so you can pick one that fits your life.
How long will it take?
Once you know your weekly rate, the timeline is simple arithmetic: to lose 10 kg at half a kilo a week takes about 20 weeks. But real progress is rarely linear — water weight, glycogen and hormones cause the scale to jump around, especially early on and around menstrual cycles. Judge progress over four-week windows, not day to day, and expect the rate to slow as you get lighter, because a smaller body burns fewer calories. To track the calendar side of a goal, the date calculator counts the weeks to a target date.
A floor worth respecting
Intakes below roughly 1,500 kcal for men and 1,200 for women make it hard to meet micronutrient needs and are usually only appropriate under medical supervision. If your calculated deficit target falls below that, lose more slowly instead.