Calculators
Calorie Deficit Calculator
Calculate the daily calorie target and estimated time to reach a goal weight from maintenance calories and a weekly loss rate.
- Runs in your browser
- Nothing uploaded
The tool
Enter your numbers below. Results update as you type, and nothing leaves your browser.
Everything you enter stays on your own machine. Nothing is sent to us or to anyone else, which you can confirm in your browser network tab.
What people use it for
- Planning a weight-loss phase
- Setting realistic timelines
- Coaching clients
- Meal plan design
About this tool
What the Calorie Deficit Calculator does
Weight loss needs a calorie deficit: eating fewer calories than you use. A commonly used approximation is that about 7,700 kcal corresponds to a kilogram of body fat (about 3,500 kcal per pound). This calculator turns a weekly loss rate into a daily target and estimates how long the goal will take.
Formula
- Daily deficit = weekly loss (kg) × 7,700 ÷ 7
- Target = maintenance − deficit (not below your minimum)
- Weeks = weight to lose ÷ weekly loss
Worked example
Using the starting values in the calculator above:
| Input | Value |
|---|---|
| Maintenance calories | 2,500 kcal |
| Current weight | 85 kg |
| Goal weight | 75 kg |
| Target loss per week | 0.5 kg |
| Minimum daily intake | 1,500 kcal |
| Result | Value |
|---|---|
| Daily calorie target | 1,950 |
| Estimated weeks to goal | 20.0 |
| Daily deficit | 550 |
| Deficit as share of maintenance | 22.0% |
| Adjusted for minimum intake | No |
How to read the result
Weight loss usually slows over time as body weight and energy needs fall; recalculate maintenance every few kilograms.
Losing about 0.5% to 1% of body weight a week helps preserve muscle, especially with adequate protein and strength training.
General information, not medical advice. Speak to a qualified health professional before making changes to diet, exercise or treatment.
Related calculators
- Calories Burned Calculator: Estimate calories burned during exercise and daily activities from body weight, duration and the activity’s MET value.
- Macros Calculator: Split a daily calorie target into grams of protein, carbohydrate and fat by percentage, with per-meal amounts.
- Protein Intake Calculator: Calculate daily protein needs from body weight and goal, with per-meal amounts and the share of calories.
- Water Intake Calculator: Estimate daily water intake from body weight, exercise and climate, as litres and glasses.
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Questions
Questions about this tool
The things clients actually want to know — costs, timelines, ownership and what happens after launch.
About 550 kcal a day below maintenance, using the 7,700 kcal per kg approximation.
No. It is a useful approximation; real loss varies with body composition and adaptation.
Very low intakes can be unsafe without supervision; many guidelines advise against going below around 1,200–1,500 kcal without medical advice.
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