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Calorie Deficit Calculator

See how many calories to eat, and when a goal weight is realistic. Pace is capped at 0.5 to 1 kg per week. This tool will not recommend going under 1,200 kcal a day.

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Activity level
Fat-loss pace
Daily calorie target
Estimated time to goal
14 days of fat at this pace. Extra kilos on the scale in week 1 are often water and glycogen, not fat.
Goal is at or above current weight. This calculator is for weight loss. Use the calorie calculator for maintain or gain.
Estimated maintenance is already near or under 1,200 kcal. Do not start an unsupervised deficit. Talk to a clinician.
That plan would fall under 1,200 kcal a day. This tool will not go that low without medical care. Calories are raised to 1,200, so the timeline is slower than the pace you picked.
That goal weight sits under BMI 18.5 for your height. That is not a healthy unsupervised target.
The 1,200 kcal floor made this deficit very small. The date is only a rough sketch - see a clinician before cutting further.
Daily deficit
Estimated time to goal
Fat in 14 days
BMR
Maintenance
5 kg of fat

14 days of fat at this pace. Extra kilos on the scale in week 1 are often water and glycogen, not fat.

Week-by-week fat-loss timeline

WeekProjected weight

The line is fat-loss pace (about 7,700 kcal per kg). Week 1 on a real scale can drop extra water. Adjust after 2 to 3 weeks of honest logging.

Keep protein around 1.2 to 2.0 g per kg while cutting. Refine protein target

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This tool provides general informational estimates only and is not medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional.

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What is a calorie deficit?

A calorie deficit means you eat less than you burn. Fat loss is slow: about 0.5 to 1 kg per week with a 500 to 750 kcal daily gap (CDC, Mayo Clinic). This calculator will not plan faster than 1 kg per week.

The week-by-week line is fat-loss pace, not what the scale does on day 3. Week 1 can drop extra water and glycogen. That is why “lose 5 kg in two weeks” is mostly a water story. Read how to lose 5 kg in two weeks for that distinction, then use this page for the honest date.

Maintenance comes from the Mifflin–St Jeor equation × activity, same as our TDEE calculator. After you have a daily target, split it with the macro calculator and keep protein with the protein calculator.

How the timeline is calculated

About 7,700 kcal is the usual planning figure for 1 kg of body fat. A 0.5 kg/week pace is roughly a 550 kcal daily deficit; 1 kg/week is about 1,100 kcal. If that would push intake under 1,200 kcal, we raise calories and stretch the timeline. Unsupervised diets under 800 kcal belong in clinic, not in a web form.

Your metabolism also shifts as you lose weight, so treat the chart as a starting plan. Log for 2 to 3 weeks, then adjust. The daily calorie calculator is better if you want maintain or gain, not a cut.

Frequently asked questions

Clear answers based on established nutrition science.

When will I lose 5 kg?
At a 0.5 to 1 kg per week fat-loss pace, 5 kg of fat takes about 5 to 10 weeks, not 14 days. A bigger first-week drop on the scale is often glycogen and water. That is the same math as how to lose 5 kg in two weeks.
What is a calorie deficit calculator?
It estimates maintenance (TDEE) from BMR × activity, subtracts a deficit in the 0.5 to 1 kg/week band, and projects a week-by-week date. It will not send you under 1,200 kcal/day without medical care.
Is 1 kg per week safe?
The CDC and Mayo Clinic treat about 0.5 to 1 kg per week as a realistic unsupervised pace. This tool will not plan faster. People who lose in that band are more likely to keep the weight off.
Why warn under 1,200 calories?
Very-low-calorie diets (often under 800 kcal) belong in clinic. This tool uses a 1,200 kcal floor as a practical unsupervised line. If your TDEE is already near that, do not start a cut from a webpage - talk to a clinician.
Sources & methodology

Formulas and reference ranges from peer-reviewed and official sources:

  • U.S. CDC. About 1 to 2 lb (0.5 to 1 kg) per week is a realistic fat-loss pace.
  • Mayo Clinic. A 500 to 750 kcal daily deficit maps to about 0.5 to 1 kg per week.
  • Mifflin MD et al., 1990 (Am J Clin Nutr). BMR equation used for maintenance calories.
  • ~7,700 kcal ≈ 1 kg of body fat (planning estimate). The first-week scale drop is often extra water and glycogen.
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