Calorie Deficit Calculator
Find your daily calorie target for weight loss based on your body stats. Uses the scientifically validated Mifflin-St Jeor formula.
What is a Calorie Deficit?
A calorie deficit occurs when you consume fewer calories than your body burns in a day. This forces your body to use stored fat as fuel — resulting in weight loss.
It is the single most scientifically proven method for weight loss. Regardless of which diet you follow — keto, low-carb, intermittent fasting, or balanced eating — they all work through the same mechanism: creating a calorie deficit.
What is TDEE?
TDEE stands for Total Daily Energy Expenditure — the total number of calories your body burns in a day including all activity. It is calculated by multiplying your BMR (Basal Metabolic Rate) by an activity multiplier.
To lose weight, eat below your TDEE. To maintain weight, eat at your TDEE. To gain weight, eat above your TDEE. Knowing your TDEE is the foundation of any successful diet plan.
How Much of a Deficit Should You Eat?
| Goal | Daily Deficit | Expected Loss |
|---|---|---|
| Mild | 250 cal/day | ~0.25 kg/week |
| Moderate | 500 cal/day | ~0.5 kg/week |
| Aggressive | 750 cal/day | ~0.75 kg/week |
Never go below 1,200 calories/day for women or 1,500 calories/day for men without medical supervision. Extreme deficits cause muscle loss and metabolic adaptation.
How This Calculator Works
This calculator uses the Mifflin-St Jeor equation — the most accurate BMR formula recommended by nutritionists and used in clinical settings.
For Men:
BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
For Women:
BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
Ready to hit your calorie target every day?
Knowing your target is step one. Tracking it consistently is where most people struggle. Caldef makes it effortless — just describe your meal and AI does the rest.
Download Caldef Free → Available on Google Play · 7-day free trial