Calories and Weight Loss: How It Really Works
The science of energy balance made simple — how many calories you burn, how a calorie deficit drives weight loss, why plateaus happen, and how to set a safe, sustainable target.
Calorie Deficit Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Daily calories to eat
2,000
- Estimated weekly weight loss
- 0.45
- Estimated monthly weight loss
- 1.95
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Calorie Deficit Calculator
The Calorie Deficit Calculator works out your daily calories to eat, along with 2 related figures in an instant. Enter maintenance calories (tdee) and daily calorie deficit and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.
- Enter the maintenance calories (tdee).
- Enter the daily calorie deficit.
- Read off your daily calories to eat, together with estimated weekly weight loss and estimated monthly weight loss — the calculator updates automatically, with no button to press.
Formula
The Calorie Deficit Calculator uses the formula:
Daily calories to eat = Maintenance calories (TDEE) - Daily calorie deficit
Worked example
For example, with maintenance calories (tdee) of 2,500 kcal and daily calorie deficit of 500 kcal, the daily calories to eat is 2,000.
| Maintenance calories (TDEE) | 2,500 kcal |
|---|---|
| Daily calorie deficit | 500 kcal |
| Daily calories to eat | 2,000 |
|---|---|
| Estimated weekly weight loss | 0.45 |
| Estimated monthly weight loss | 1.95 |
Results are estimates for educational use, not professional advice.
Key terms explained
- Calorie
- A unit of energy from food; daily needs depend on weight, activity and goals.
Frequently asked questions
It is eating fewer calories than you burn. With a 2500-calorie maintenance and a 500-calorie deficit, you would eat 2000 calories a day.
Roughly 7700 calories equal one kilogram of fat, so a 500-calorie daily deficit loses about 0.45 kg per week.
A moderate deficit of around 300–500 calories is sustainable for most people. Very large deficits can cost muscle and are hard to maintain.
No. Water balance, muscle and metabolism cause week-to-week variation. The estimate shows the trend over time, not a guaranteed weekly figure.
The Calorie Deficit Calculator uses the formula: Daily calories to eat = Maintenance calories (TDEE) - Daily calorie deficit. For example, with maintenance calories (tdee) of 2,500 kcal and daily calorie deficit of 500 kcal, the daily calories to eat is 2,000.
Enter the maintenance calories (tdee). Enter the daily calorie deficit. Read off your daily calories to eat, together with estimated weekly weight loss and estimated monthly weight loss — the calculator updates automatically, with no button to press.
Related guides
Calorie Deficit Table: Daily calories to eat by Maintenance calories (TDEE)
Reference table of daily calories to eat for Calorie Deficit across a range of maintenance calories (tdee) values — exact, engine-computed figures you can read off at a glance.
How to Calculate Calorie Deficit: Formula, Steps & Examples
Learn how to calculate Calorie Deficit — the formula explained step by step, with worked examples and a free calculator to check your answer.