Calorie Deficit Calculator - Daily Calories to Lose Weight & Goal Date
Calorie Deficit Calculator
Turn a weight goal and a pace into a daily calorie target
A Daily Target
Subtract the deficit from your maintenance calories to get a concrete number of calories to eat each day.
A Goal Date
See how many weeks your pace takes and the calendar date you could reach your goal weight.
Safety Checks
Warnings appear for paces above 1% of body weight a week, very large deficits and targets below 1,200 kcal.
Full Privacy
Everything is calculated in your browser.
How the Calorie Maths Works
A rule of thumb says a kilogram of body weight holds about 7,700 kcal (3,500 kcal per pound). Losing 0.5 kg a week therefore needs a deficit of about 3,850 kcal a week, or 550 kcal a day. From 2,500 kcal of maintenance that means eating about 1,950 kcal, and losing 5 kg would take about 10 weeks.
Real life is less tidy than the formula. Your maintenance calories fall as you lose weight, water shifts change the scale, and progress is rarely a straight line, so treat the date as a rough guide and recheck every few weeks. This is general information, not medical advice: if you have a health condition, are pregnant or breastfeeding, are under 18, or have a history of disordered eating, speak to a doctor or dietitian before dieting.
Key Takeaways
- Both unit systems: kg or lb, converted automatically when you switch.
- Built-in warnings: Flags fast paces, big deficits and very low calorie targets.
- Information only: Not a diagnosis or medical advice.