Calorie Deficit Calculator
Find your daily calorie target and how long it will take to reach your goal weight.
Slow
0.25 kg/week
0.25 kg/week
Moderate
0.5 kg/week
0.5 kg/week
Fast
0.75 kg/week
0.75 kg/week
Please fill in all fields with valid values.
Your TDEE
kcal/day
Target Calories
kcal/day
Daily Deficit
kcal/day
Time to Goal
weeks
Your Plan
What this means for your goals
What is a Calorie Deficit?
A calorie deficit occurs when you consume fewer calories than your body burns in a day. Your body responds by tapping into stored fat for energy, which leads to weight loss over time.Your total daily calorie burn — known as your TDEE (Total Daily Energy Expenditure) — is the baseline. Eat below that number consistently and you will lose weight. The size of your deficit determines how fast you lose it.
The key numbers to understand:
- 1 kg of fat = approximately 7,700 calories. To lose 1 kg per week you need a deficit of ~1,100 kcal/day — which is aggressive for most people
- 0.5 kg per week requires a daily deficit of ~550 kcal — the most common recommendation for sustainable fat loss
- 0.25 kg per week requires a deficit of ~275 kcal/day — ideal for those close to their goal or wanting to minimize muscle loss
How to Use Your Calorie Deficit
Fat Loss
A calorie deficit is the only proven method for losing body fat. The size of your deficit determines your pace — but bigger is not always better. Too large a deficit leads to muscle loss, fatigue, and metabolic adaptation. A moderate deficit of 300–500 kcal/day hits the sweet spot for most people.- Slow cut (275 kcal deficit): Minimal hunger, maximum muscle retention — best for athletes and those close to goal weight
- Moderate cut (550 kcal deficit): The most popular approach — steady fat loss with manageable hunger
- Aggressive cut (800+ kcal deficit): Faster results but higher risk of muscle loss — only recommended short term with very high protein intake
Maintenance
If your goal is maintenance, your calorie deficit is zero — you eat exactly at your TDEE. Use our TDEE Calculator to find your exact maintenance number, then track your weight weekly to confirm it is holding steady.Muscle Gain
Building muscle requires a calorie surplus, not a deficit. However, body recomposition — losing fat while gaining muscle simultaneously — is possible when eating near maintenance with high protein and progressive resistance training. This works best for beginners and those returning after a break.How Long Will It Take to Reach Your Goal Weight?
Fat loss timelines depend on three things: how much you want to lose, your daily deficit, and your consistency. Use the calculator above to get your personalized estimate.As a general guide:
- 5 kg to lose: 10–20 weeks depending on pace
- 10 kg to lose: 20–40 weeks depending on pace
- 20 kg to lose: 40–80 weeks depending on pace
Related Calculators
- TDEE Calculator — Find your total daily calorie needs
- BMR Calculator — Calculate your basal metabolic rate
- Protein Calculator — Find your ideal daily protein intake
- Macro Calculator — Break your calories into protein, carbs, and fat
- BMI Calculator — Calculate your Body Mass Index
- Body Fat % Calculator — Estimate your body fat percentage
Calorie Deficit calculator FAQ
How do I calculate my calorie deficit?
Subtract your target daily calories from your TDEE. For example, if your TDEE is 2,500 kcal and you eat 2,000 kcal, your deficit is 500 kcal/day. Over 7 days that is a 3,500 kcal weekly deficit — enough to lose approximately 0.45 kg per week.
Is a 500 calorie deficit safe?
Yes — a 500 kcal/day deficit is widely considered safe and sustainable for most healthy adults. It produces roughly 0.5 kg of fat loss per week without significantly impacting energy levels or muscle mass, especially when paired with adequate protein intake.
What happens if my deficit is too large?
Deficits above 1,000 kcal/day increase the risk of muscle loss, nutrient deficiencies, fatigue, and metabolic adaptation — where your body lowers its calorie burn in response to prolonged restriction. This makes long-term fat loss harder. Staying in a moderate deficit is more effective over time.
Should I eat back calories burned during exercise?
It depends on how your TDEE was calculated. If your activity level already accounts for your workouts, do not eat them back. If you selected a sedentary multiplier and exercise on top of that, eating back 50–75% of burned calories is a reasonable approach to avoid too large a deficit.
Why am I not losing weight in a calorie deficit?
The most common reasons are underestimating calorie intake, overestimating portions, or not accounting for liquid calories and cooking oils. Weigh your food with a kitchen scale for 2 weeks to get an accurate picture. Water retention from high sodium, stress, or new training can also mask fat loss on the scale for 1–2 weeks.
How much protein should I eat in a calorie deficit?
Aim for 1.6–2.2g of protein per kg of bodyweight while cutting. Higher protein intake preserves muscle mass, keeps you fuller for longer, and has a higher thermic effect — meaning your body burns more calories digesting it compared to carbs or fat. Use our Protein Calculator to find your exact target.