Calorie Deficit Calculator: How Many Calories to Eat to Lose Weight
Short answer
To lose weight, eat fewer calories than your maintenance level. Multiply the kilograms you want to lose by 7,700 kcal, divide by the number of days in your timeline, and subtract that daily deficit from your maintenance calories. Losing 5 kg in 10 weeks needs a deficit of 550 kcal a day.
Not sure? Use the calorie calculator first.
Daily calorie target
1,776
kcal/day
Daily deficit
624
kcal/day
Weekly loss
1.25 lb
per week
This calorie deficit calculator shows how many calories to eat each day to reach a goal weight by a set date. Enter your maintenance calories, current weight, goal weight and the number of weeks, and you get the daily calorie deficit, a daily calorie target and the weekly weight loss the plan requires.
If you don’t know your maintenance calories, start with the calorie calculator, which estimates them from age, height, weight and activity. Results are estimates and not medical advice. Anyone with a medical condition, who is pregnant or who has a history of disordered eating should plan weight loss with a doctor or dietitian.
How to use the calorie deficit calculator
- 1
Enter your maintenance calories
The calories you eat per day while your weight stays stable. Use the calorie calculator, or better, your average intake over two to three weeks of stable weight.
- 2
Enter your current and goal weight
In kg (1 kg is about 2.2 lb). The difference is the amount of weight the plan aims to lose.
- 3
Choose the number of weeks
How long you want the plan to take. A longer timeline means a smaller daily deficit.
- 4
Read your results
You get the daily deficit, the daily calorie target and the weekly loss. If the deficit is above 1,000 kcal a day or the weekly loss is above 1% of your body weight, the calculator shows a warning. Add weeks until it goes away.
How is a calorie deficit calculated?
The calorie deficit calculator multiplies the weight you want to lose in kg by 7,700, the common estimate of calories in 1 kg of body fat, and divides by the number of days in your timeline. Your daily calorie target is maintenance calories minus that deficit, and weekly weight loss is the total to lose divided by the number of weeks.
- Daily deficit: (current weight − goal weight) × 7,700 ÷ (weeks × 7).
- Daily calorie target: maintenance calories − daily deficit.
- Weekly loss: (current weight − goal weight) ÷ weeks.
Example: at 85 kg with a goal of 78 kg in 14 weeks, the deficit is 7 × 7,700 ÷ 98 = 550 kcal a day. With maintenance of 2,600 kcal, the target is 2,050 kcal a day, and the plan asks for 0.5 kg of loss per week, well under 1% of body weight (0.85 kg).
How big should a calorie deficit be?
For most people, a deficit that produces a loss of about 0.5 to 1% of body weight per week is a sensible target, and the calculator flags any plan faster than 1% a week or bigger than 1,000 kcal a day.
A deficit of about 500 kcal a day, the default in the calorie calculator, works out to roughly 0.5 kg (1 lb) a week. Bigger deficits are harder to sustain: hunger rises, training quality drops and holding on to muscle gets harder. Lean or smaller people usually need a smaller deficit than people with more weight to lose, which is why the warning is tied to body weight.
Why doesn’t real weight loss match the calculator?
Because 7,700 kcal per kg is a rule of thumb, not a law, and the scale measures more than fat.
- Water and glycogen. The first week or two often shows a bigger drop as stored carbs and water go down. After that, the scale moves slower and less evenly.
- Maintenance is an estimate. If true maintenance is 200 kcal lower than the number entered, the real deficit is 200 kcal smaller.
- The body adapts. As weight drops, maintenance calories drop too, so the same intake produces a smaller deficit over time. Recalculate every few kilograms.
- Daily fluctuations. Salt, carbs, sleep, stress and the menstrual cycle move scale weight from day to day. Compare weekly averages, not single weigh-ins.
How coaches use a calorie deficit with clients
Personal trainers and online coaches use the deficit to turn a client’s goal into a daily number, and the timeline to set expectations before the first weigh-in. When a client wants to lose 10 kg in six weeks, a calorie deficit calculator shows the deficit that would take, and the warning makes the case for a longer plan.
- Agree on the timeline first. Set the goal weight and the number of weeks together with the client, so the calorie target comes from a plan they accepted.
- Adjust from real data. After two to three weeks, compare actual weekly loss with the plan. If it’s slower, lower intake a little or add activity. If it’s faster than 1% a week, add food.
- Protect muscle. Keep protein high and strength training in the program during the deficit. The protein calculator and macro calculator help split the calorie target into macros.
On the Coach+ coaching platform, you set calorie and macro targets in each client’s meal plan, and clients log food in your branded app by barcode, photo or search, so you see daily intake against the target. Weekly check-ins with progress photos show whether the deficit is working, and the AI assistant can draft a meal plan at the new calorie level for you to review.
Frequently asked questions
How many calories should I eat to lose weight?
Subtract your daily deficit from your maintenance calories. A deficit of about 500 kcal a day leads to roughly 0.5 kg (1 lb) of loss per week, so with maintenance of 2,400 kcal you would eat about 1,900 kcal a day.
How many calories are in 1 kg of fat?
The common estimate is about 7,700 kcal per kg, or about 3,500 kcal per pound. It’s a useful planning number, but real weight loss varies because of water, glycogen and changes in maintenance calories.
Is a 1,000 calorie deficit too much?
For many people it is aggressive, and the calculator warns above 1,000 kcal a day. Someone with a lot of weight to lose may handle it for a while, but leaner or smaller people usually do better with a smaller deficit that keeps weekly loss under 1% of body weight.
How long does it take to lose 10 kg?
At 0.5 kg per week it takes about 20 weeks, and at 1 kg per week about 10 weeks. Losing 10 kg in 20 weeks needs a daily deficit of 10 × 7,700 ÷ 140 = 550 kcal.
Why am I not losing weight in a calorie deficit?
Most often the deficit is smaller than planned: maintenance was overestimated or intake is higher than logged. Water retention can also hide fat loss for a week or two, so judge progress from weekly averages over at least two to three weeks.
