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Free Calorie Deficit Calculator

A calorie deficit means consuming fewer calories than your body burns each day. This calculator helps you set a sustainable deficit based on your TDEE so you can lose weight steadily without extreme restriction.

Calculate Your Calorie Deficit

Enter your details and choose a deficit level to get your daily calorie target.

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Choosing the Right Deficit

10% (Mild)

Very gradual. Best for those close to their goal weight or concerned about muscle loss.

Est. rate: ~0.1–0.2 kg/week

15% (Moderate)

Steady, comfortable pace. Good balance of sustainability and results.

Est. rate: ~0.2–0.3 kg/week

20% (Standard)

The most commonly recommended range for healthy weight loss. Still allows adequate nutrition.

Est. rate: ~0.3–0.5 kg/week

25% (Higher)

Faster progress but requires discipline and careful attention to protein intake to protect muscle mass.

Est. rate: ~0.4–0.7 kg/week

These are general estimates. Real weight change depends on many factors including water retention, hormones, and metabolic adaptation.

How many calories to lose 1kg a week?

About 7,700 kcal is a commonly used planning estimate for 1 kg of body fat. Losing 1 kg in seven days would imply a deficit of roughly 1,100 kcal per day, which is too aggressive for many people. A 500 to 700 kcal daily deficit is usually more sustainable and should be adjusted using real weight trends.

How the Calculation Works

1. Calculate your TDEE (BMR × activity multiplier)

2. Apply your chosen deficit percentage: Daily Target = TDEE × (1 − deficit%)

3. Your weekly deficit = Daily Deficit × 7

Example: TDEE of 2,500 kcal with 20% deficit → Daily Target = 2,500 × 0.80 = 2,000 kcal/day

How the Calculation Works

Asterisks Fit calorie deficit thresholds are formulated based on clinical metabolic studies and evidence-based nutrition science:

  • Academy of Nutrition and Dietetics Guidelines: Recommends a structured, moderate deficit of 10% to 25% of TDEE to achieve safe, sustainable weight loss (approximately 0.25 to 1.0 kg per week) while preserving lean skeletal muscle tissue.
  • Dynamic Metabolic Modeling (Hall et al., 2011):Acknowledges that weight loss is non-linear. Standard static calculations (e.g., Wishnofsky's 3,500 kcal per pound rule) serve as initial mathematical estimates, but real-world adaptations involve metabolic slowing (adaptive thermogenesis) as body mass decreases, highlighting the need for regular progress reviews.
  • Nutritional Adequacy Thresholds: Our system enforces built-in safety baselines (e.g., not recommending targets below standard clinical floors of 1,200 kcal/day for females and 1,500 kcal/day for males unless supervised by a clinical dietitian) to prevent micronutrient deficiencies and metabolic dysfunction.
Formula based on the published equation. Methodology reviewed by the Asterisks editorial team. Last content review: August 2026.
Last Updated: June 2026

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Want a Deficit Plan That Is Sustainable?

Extreme deficits lead to burnout. Work with a coach to design calorie targets and macro splits that preserve muscle and keep energy high.

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Frequently Asked Questions

Medical Disclaimer: Calorie targets are estimates. Always eat enough to meet your nutritional needs. Do not follow extreme deficits without medical supervision. Full disclaimer →