Calorie Deficit Calculator
Work out the exact calorie deficit you need to reach your goal weight safely. This calculator shows your maintenance calories, recommended deficit, daily intake target, and an estimated timeline to reach your goal.
What You'll Get
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Enter your details
Your Calorie Deficit Plan
ExampleExample figures, not your own. Worked for a lightly active 35 year old woman of 85 kg and 165 cm aiming for 70 kg on a moderate deficit. Enter your own details and press Calculate.
Basal Metabolic Rate
6,464kJ/day
Calories burned at complete rest
Maintenance (TDEE)
8,891kJ/day
To maintain current weight
Your Daily Target
7,113kJ/day
1,778 kJ deficit per dayEstimated Weekly Loss
0.4kg/week
Healthy rate of lossEstimated Time to Goal
39weeks
To reach 70 kg (9 months)
Total Weight to Lose
15kg
From 85 kg to 70 kg
What Does This Look Like?
Your daily deficit of 1,778 kJ is roughly equivalent to cutting out a blueberry muffin each day.
Or, you could burn the same amount with a 66-minute brisk walk (5 km/h).
Deficit Level Comparison
| Level | Daily Target | Deficit/Day | Weekly Loss | Time to Goal |
|---|---|---|---|---|
| Mild (10%) | 8,000 kJ | 887 kJ | 0.19 kg | 78 weeks |
| Moderate (20%) | 7,113 kJ | 1,778 kJ | 0.39 kg | 39 weeks |
| Aggressive (25%) | 6,669 kJ | 2,222 kJ | 0.48 kg | 32 weeks |
| Extreme (30%) | 6,222 kJ | 2,665 kJ | 0.58 kg | 26 weeks |
Recommended Macro Split
A 40/30/30 protein-focused split is recommended during a calorie deficit to help preserve lean muscle mass.
Suggested Per-Meal Breakdown
| Meal | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|
| Breakfast | 425 | 43g | 32g | 14g |
| Lunch | 510 | 51g | 38g | 17g |
| Dinner | 510 | 51g | 38g | 17g |
| Snacks | 255 | 26g | 19g | 9g |
| Daily Total | 1700 | 170g | 128g | 57g |
Projected Weight Loss Timeline
| Week | Projected Weight | Daily Target |
|---|---|---|
| Start | 85.0 kg | 7,113 kJ/day |
| Week 4 | 83.5 kg | 7,042 kJ/day |
| Week 8 | 81.9 kg | 6,971 kJ/day |
| Week 12 | 80.4 kg | 6,899 kJ/day |
| Week 16 | 78.8 kg | 6,828 kJ/day |
| Week 20 | 77.3 kg | 6,757 kJ/day |
| Week 24 | 75.7 kg | 6,686 kJ/day |
| Week 28 | 74.2 kg | 6,615 kJ/day |
| Week 32 | 72.6 kg | 6,544 kJ/day |
| Week 36 | 71.1 kg | 6,473 kJ/day |
| Week 40 | 70.0 kg | 6,422 kJ/day |
Daily target decreases over time as your weight drops and your body needs fewer calories to maintain.
How It Works
Your maintenance calories are calculated using the Mifflin-St Jeor equation multiplied by your activity factor. The deficit is the difference between your maintenance level and your target intake. Since approximately 7,700 kcal (32,200 kJ) equals one kilogram of body fat, your weekly weight loss is determined by your daily deficit multiplied by 7, divided by 7,700.
How to use it
- 1Enter your gender, age, weight, height, and activity level
- 2Enter your goal weight in kilograms
- 3Select your preferred deficit level (mild, moderate, or aggressive)
- 4Click "Calculate" to see your daily target, deficit, and timeline
Quick Reference
| Deficit Level | Deficit | Weekly Loss | Time to Lose 10 kg |
|---|---|---|---|
| Mild (10%) | ~800 kJ/day | ~0.25 kg | ~40 weeks |
| Moderate (20%) | ~1,600 kJ/day | ~0.5 kg | ~20 weeks |
| Aggressive (25%) | ~2,100 kJ/day | ~0.75 kg | ~14 weeks |
| Extreme (30%) | ~2,500 kJ/day | ~1.0 kg | ~10 weeks |
Approximate values for a person with 8,400 kJ/day maintenance. Actual results vary by individual.
How This Is Calculated
- BMR
- = Basal Metabolic Rate from Mifflin-St Jeor equation
- Activity Factor
- = 1.2 (sedentary) to 1.9 (very active)
- 7,700
- = Approximate kcal in 1 kg of body fat
The 7,700 kcal per kg figure is an average. Actual fat loss may differ due to water retention, metabolic adaptation, and changes in lean mass.