What is a calorie deficit?

A calorie deficit occurs when you consume fewer calories than your body needs to maintain its current weight. This forces the body to use stored energy (primarily fat) as fuel.

How much calorie deficit is safe?

A deficit of 300-500 kcal/day is generally safe and sustainable, resulting in 0.25-0.5 kg loss per week. Extreme deficits (>1000 kcal) can cause muscle loss, metabolic slowdown and nutrient deficiencies.

How much weight can I lose per week?

A safe, sustainable rate is 0.25-0.75 kg per week. Losing more than 1 kg per week often involves muscle loss and is difficult to maintain long-term.

Should I calculate my deficit daily or weekly?

Both approaches work. A weekly target (e.g., 3500 kcal deficit per week) gives you flexibility to eat more on some days and less on others, which many people find more sustainable.

What are the risks of an extreme calorie deficit?

Extreme deficits can lead to muscle loss, hormonal disruption, fatigue, nutrient deficiencies, and metabolic adaptation where your body burns fewer calories to compensate. This makes further weight loss harder.

Can I exercise while in a calorie deficit?

Yes, and it's recommended. Resistance training helps preserve muscle mass during a deficit, while cardio can increase your energy expenditure. Just ensure your deficit isn't so large that you can't recover from your workouts.

What if my weight loss stalls?

Plateaus are normal. As you lose weight, your TDEE decreases. Recalculate your deficit with your current weight, check if activity has changed, and ensure you're tracking intake accurately. Patience and consistency are key.

Calorie Deficit Calculator

Calculate the calorie deficit you need for sustainable weight loss. Enter your details and we'll show you the recommended calories and macros to reach your goal safely.

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How We Calculate

Our calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR), then applies an activity multiplier to determine your Total Daily Energy Expenditure (TDEE). Macronutrients are distributed based on evidence-backed guidelines: protein is set according to body weight and goal, fat is kept within healthy minimums, and carbohydrates fill the remaining calories. The algorithm enforces safety limits including calorie floors and maximum deficit caps.

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