Calorie Deficit & Weight Loss Timeline Calculator
Find your daily calorie deficit, weekly weight loss and how many weeks it takes to reach your goal weight
Calorie Deficit & Weight Loss Timeline Calculator
Find your daily calorie deficit, weekly weight loss and how many weeks it takes to reach your goal weight
What Is a Calorie Deficit and How Long Does Weight Loss Take?
A calorie deficit means eating fewer calories than your body uses each day. The widely used approximation is that about 7,700 kcal equals 1 kg of body fat (roughly 3,500 kcal per pound), so a steady deficit of 500 kcal per day leads to about 0.45 kg (1 lb) of fat loss per week.
This calculator takes your current weight, goal weight, maintenance calories and daily intake, then estimates the daily deficit, the weekly loss, how long it will take to reach the goal and roughly when that date falls.
How to Use This Calculator
Why Pace Matters as Much as the Number
Very large deficits can cost muscle, energy and training quality, and they are harder to sustain. A common guideline is to aim for about 0.5% to 1% of body weight per week, which is why the result shows your weekly loss as a percentage of body weight.
Weight loss is rarely a straight line. Water weight, glycogen and the fact that maintenance calories fall as weight drops all change the picture, so treat the timeline as a planning estimate and re-check your numbers every few weeks.
?Frequently Asked Questions
Most guidance suggests a moderate deficit of about 300 to 700 kcal per day, or roughly 10% to 25% below maintenance. Larger deficits are possible but harder to sustain and can reduce muscle and training performance.
Your maintenance level is your total daily energy expenditure (TDEE). Use the TDEE calculator on this site, or track your weight and intake for two to three weeks and see the intake at which your weight stays steady.
No, it is an approximation. Real weight changes also include water, glycogen and lean tissue, and your maintenance calories fall as you lose weight, so progress usually slows over time.
Many health bodies suggest not going below about 1,200 kcal per day for women or 1,500 kcal per day for men without medical supervision. The calculator warns you if your intake is below 1,200.
A lighter body burns fewer calories, and the body can adapt to lower intake, so the same intake gives a smaller deficit over time. Recalculate with your new weight and maintenance every few weeks.
Yes. Maintenance calories already include your usual activity. If you add more exercise, either raise your maintenance figure or treat the extra burn as additional deficit.