Calorie Deficit Calculator
Find your daily calorie target and timeline to reach a goal weight, safely.
How This Works
We calculate your maintenance calories (TDEE) using the Mifflin-St Jeor formula, then apply a deficit based on your chosen pace. 1 kg of fat is roughly 7,700 calories.
A deficit larger than ~1 kg/week is generally not recommended without medical supervision — it can be harder to sustain and may cause muscle loss. Consult a healthcare provider before starting any weight-loss plan.
How This Calculator Works
This tool estimates your maintenance calories (TDEE) using the Mifflin-St Jeor BMR formula and your activity level, then applies a calorie deficit or surplus based on your chosen pace of change:
Your chosen weekly pace (e.g. 0.5 kg/week) is converted into a daily calorie deficit, then subtracted from (or added to) your maintenance calories to set your daily target.
Choosing a Safe Pace
A deficit of roughly 0.5 kg (about 1 lb) per week is a commonly recommended, sustainable pace for most adults. Faster rates can be harder to maintain and may increase the risk of muscle loss alongside fat loss — pair this with adequate protein intake, which our BMR Analysis tool can help you plan.
Limitations
This is an estimate based on population-average formulas. Actual results vary with individual metabolism, adherence, sleep, stress, and hormonal factors. Weight loss also isn't perfectly linear week to week.
Frequently Asked Questions
Is a bigger calorie deficit always better for faster results?
Not necessarily — very large deficits are harder to sustain, can increase muscle loss, and may slow down your metabolism over time. A moderate, sustainable deficit is generally recommended.
Why does my estimated timeline look different from what I expected?
This calculator gives a straight-line estimate based on a fixed weekly pace. Real progress often varies week to week due to water retention, hormones, and adherence.
Should I eat back calories burned from exercise?
This calculator's activity multiplier already accounts for general activity level, so most people don't need to separately add back exercise calories unless doing unusually intense training.