Calorie Deficit Calculator

A calorie deficit means eating fewer calories than you burn, forcing your body to draw on stored energy (fat). This calculator turns a weekly weight-loss goal into a concrete daily calorie target.

Fill in the form and select Calculate to see your result here.

What is Calorie Deficit?

This calculator converts a target rate of weekly fat loss into the daily calorie deficit required to achieve it, using the widely cited estimate that roughly 7,700 kcal of deficit corresponds to about 1 kg of body fat.

Calorie Deficit Formula

The weekly loss goal (in kg) is converted to a total weekly calorie deficit, then divided across 7 days to get a daily number, which is subtracted from your maintenance calories.

Daily Deficit = (Weekly Loss Goal (kg) × 7700) ÷ 7
Target Calories = Maintenance Calories − Daily Deficit

Calorie Deficit Example

With 2500 maintenance calories and a 0.5 kg/week goal: daily deficit = (0.5 × 7700) ÷ 7 ≈ 550 kcal, so target calories = 2500 − 550 = 1950 kcal/day.

How to Use This Calculator

Enter your maintenance calories (from the TDEE Calculator).
Choose your desired weekly weight loss rate.
Select "Calculate" to see your daily deficit and target calorie intake.

Limitations

7,700 kcal per kg of fat is a population average — individual metabolic adaptation, water weight fluctuation and NEAT changes mean real results vary.
Faster weight loss goals (0.75-1 kg/week) increase the risk of muscle loss and are harder to sustain — a moderate deficit is generally easier to stick to long-term.
Very low resulting calorie targets (well under 1200-1500 kcal/day) are not recommended without professional supervision.

Frequently Asked Questions

For most healthy adults, 0.5-1% of body weight per week (often roughly 0.25-0.75 kg/week) is considered a sustainable rate that preserves more muscle than very aggressive deficits.

As you lose weight, your maintenance calories drop too, shrinking your effective deficit over time. Recalculate your TDEE every few kilograms lost and adjust your target accordingly.

Yes — resistance training alongside a calorie deficit helps preserve lean muscle mass while you lose fat. See the Workout and Protein Calculator sections.