Calorie Deficit Calculator
This calculator subtracts your daily intake from your maintenance calories to find a daily deficit, then projects a weekly fat loss by scaling the weekly deficit against 7700 kcal per kilogram and 3500 kcal per pound.
What this calculator does
The Calorie Deficit Calculator estimates your result instantly from the values you enter, using standard health & fitness formulas. This calculator subtracts your daily intake from your maintenance calories to find a daily deficit, then projects a weekly fat loss by scaling the weekly deficit against 7700 kcal per kilogram and 3500 kcal per pound. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.
Result
About Calorie Deficit Calculator
The Calorie Deficit Calculator takes your maintenance calories and your daily intake and subtracts to get a daily deficit. It multiplies that deficit by 7 for a weekly total, then divides by 7700 for kilograms and by 3500 for pounds of projected fat loss.
The daily deficit is shown as a whole number and the weekly loss as kilograms with pounds in parentheses.
Formula & Mathematical Calculation
Daily Deficit (kcal) = f(Maintenance Calories (kcal), Daily Intake (kcal))
Calculated according to standard health formulas implemented in the calculator core.
Calculation Example
Enter maintenance calories of 2400 and a daily intake of 1900. The daily deficit is 2400 - 1900 = 500 kcal.
Weekly, that is 500 × 7 = 3500 kcal, which is 3500 ÷ 7700 = 0.45 kg or 3500 ÷ 3500 = 1 lb. The boxes show 500 kcal and 0.45 kg (1 lb).
Key Benefits
- Finds your daily calorie deficit from two entries in one step.
- Projects weekly fat loss using 7700 kcal per kilogram and 3500 kcal per pound.
- Shows the weekly loss in both kilograms and pounds together.
- Free, browser-based, and requires no sign-up.
How to Use this Calculator
-
Enter maintenance calories
Type your maintenance calories in the Maintenance Calories (kcal) field. -
Enter daily intake
Type your daily calorie intake in the Daily Intake (kcal) field. -
Calculate
Select Calculate to see the Daily Deficit and projected Weekly Fat Loss.
Assumptions & Limitations
What the calculation assumes
- Every value you enter is treated as an exact, known amount.
- Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
- Results use standard published formulas and account only for the values entered above.
- Rounding is applied for display; the underlying calculation uses your full precision.
- Results are returned in the same units you enter, unless the tool states the output unit.
What it does not cover
- Calorie Deficit Calculator produces a calculated result for reference and learning, not a certified or official measurement.
- Real-world outcomes differ when tolerances, rounding rules or local standards apply.
- Definitions and standards vary by region and change over time; verify the convention that applies to your case.
- Figures are only as accurate as the inputs you supply — check them before acting on the result.
- For work where the result carries real consequences, confirm it against an authoritative source.
Frequently Asked Questions
Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.