Calorie Deficit Calculator
Calculate the exact calorie deficit you need to reach your weight loss goal. See how long it will take to lose your target weight safely and sustainably.
Calculate Your Calorie Deficit
What Is a Calorie Deficit?
A calorie deficit occurs when you consume fewer calories than your body burns (your TDEE). Your body then uses stored energy (body fat) to make up the difference, resulting in weight loss.
The rule of thumb: 3,500 calories ≈ 1 pound of fat. A 500 kcal/day deficit creates a ~3,500 kcal weekly deficit, leading to approximately 1 lb (0.45 kg) of fat loss per week.
How Much of a Deficit Is Safe?
- Mild (−250 kcal/day) — Minimal muscle loss risk, sustainable long-term, ~0.5 lb/week
- Moderate (−500 kcal/day) — Most recommended, balances speed and muscle retention, ~1 lb/week
- Aggressive (−750 kcal/day) — Faster fat loss but increases muscle loss risk, ~1.5 lb/week
- >1,000 kcal/day — Not recommended without medical supervision
⚠️
Important
Never eat below 1,200 kcal/day (women) or 1,500 kcal/day (men) without medical supervision. Very low calorie diets can cause muscle loss, nutritional deficiencies, and metabolic adaptation.
More Free Tools
Related Free Calculators
🔥
TDEE Calculator
Don't have your TDEE yet? Calculate your Total Daily Energy Expenditure first — it's the input this deficit calculator needs.
Calculate TDEE →
⚖️
Maintenance Calories Calculator
Find your maintenance calories across all activity levels — use that number directly as input for this deficit calculator.
Find Maintenance Calories →
🥗
Macro Calculator
Once you have your deficit calorie target, use this to split it into optimal protein, carbs, and fat for fat loss.
Calculate Macros →
🧬
BMR Calculator
Understand the resting component of your TDEE. A higher BMR means a higher maintenance level and more flexible deficit options.
Calculate BMR →
📊
Body Fat Calculator
Track your body fat % to ensure you're losing fat (not muscle) during your calorie deficit. Use alongside this calculator.
Estimate Body Fat →