📉 Calorie Deficit Calculator
How many calories to eat to lose weight
Written by Albert Mateos · Founder & Editor
Last reviewed: May 2, 2026
How it works
Calculate exactly how many calories you need to eat to lose weight at your desired pace. Enter your current weight, goal weight, and timeframe to get a personalized daily calorie target. See your required deficit, estimated TDEE, and weekly weight loss rate. Safe, sustainable, science-based.
How to Use This Calculator
- Enter your current weight, target weight, and timeframe for the goal.
- Input your TDEE or calculate it first if unknown.
- Review the required daily calorie deficit.
- Check whether the deficit falls within a safe and sustainable range.
- Adjust the timeline if the recommended deficit is too aggressive.
Example
Inputs: Current 85 kg, target 75 kg, goal within 20 weeks, TDEE of 2,600 kcal.
Result: Required daily deficit of 550 kcal, eating 2,050 kcal per day.
What it means: This produces a steady 0.5 kg per week loss, preserves lean mass, and stays within the 500-750 kcal deficit range most experts recommend.
Tips
- A deficit of 20-25% below TDEE is the sweet spot. Anything deeper risks significant muscle loss and metabolic slowdown.
- Aim for 0.5-1% of body weight lost per week. Faster rates strongly bias toward muscle and water loss rather than fat.
- Expect a 10-20% metabolic adaptation during a cut. Your TDEE drops more than pure weight loss alone would predict.
- Schedule refeed days or diet breaks every 8-12 weeks at maintenance calories. They restore leptin, improve adherence, and break plateaus.
- Track by weekly averages, not daily fluctuations. Water, glycogen, and bowel content can shift scale weight by 1-2 kg day to day.
Learn More
TDEE Explained: Your Complete Guide to Daily Calories
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Is 1200 Calories Enough? The Truth About Very Low Calorie Diets
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How to Calculate Macros for Weight Loss: Step-by-Step
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How to Lose Weight Fast (Safely and Sustainably)
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How to Lose Belly Fat: What Actually Works
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Frequently Asked Questions
- What's a safe rate of weight loss?
- 0.5-1 kg (1-2 lbs) per week is generally considered safe and sustainable. Faster rates increase muscle loss risk and are harder to maintain. A 500 calorie daily deficit produces roughly 0.5 kg/week loss.
- What's the minimum calories I should eat?
- General guidelines suggest men shouldn't go below 1,500 cal/day and women below 1,200 cal/day without medical supervision. Very low calorie diets can cause muscle loss, nutrient deficiencies, metabolic adaptation, and are hard to sustain.
- Why has my weight loss stalled?
- Plateaus are normal. As you lose weight, your TDEE decreases (lighter body = fewer calories burned). Recalculate your TDEE with your current weight. Also consider: water retention (especially with new exercise), measurement timing, and whether you're accurately tracking intake.
Authoritative resources
We recommend these external sources for further reading from recognized health organizations and peer-reviewed literature:
- Quantification of energy imbalance on bodyweight (Hall) — The Lancet / PubMed
- Sustainable weight loss strategies — CDC
Scientific References
This calculator is based on peer-reviewed research and established health guidelines:
- Hall KD, Sacks G, Chandramohan D, et al.. Quantification of the effect of energy imbalance on bodyweight. The Lancet, 378(9793): 826-837. 2011.