Calorie Deficit Calculator
Estimate your maintenance calories (TDEE) and a sustainable daily calorie target for fat loss.
What Is a Calorie Deficit?
A calorie deficit means you consume fewer calories than your body uses in a day. Over time, this energy gap can lead to weight loss. Your body still needs fuel for breathing, digestion, movement, and recovery, so the goal is not to eat as little as possible—it is to create a controlled, sustainable deficit.
Most people lose fat best when they follow a moderate deficit they can maintain for months, not days. Consistency beats extremes.
How to Calculate Calorie Deficit the Smart Way
1) Estimate your BMR
BMR (Basal Metabolic Rate) is the calories your body burns at rest. This calculator uses the Mifflin-St Jeor equation, one of the most common evidence-based formulas.
2) Estimate your TDEE
TDEE (Total Daily Energy Expenditure) is your true maintenance level. It equals BMR multiplied by your activity factor. This tells you roughly how many calories keep your weight stable.
3) Subtract a deficit based on your goal
A practical approach is to choose a weekly fat-loss rate, then convert it to a daily calorie deficit. Roughly speaking, 1 kg of body fat is about 7,700 kcal, so:
- 0.25 kg/week ≈ 275 kcal/day deficit
- 0.50 kg/week ≈ 550 kcal/day deficit
- 0.75 kg/week ≈ 825 kcal/day deficit
- 1.00 kg/week ≈ 1,100 kcal/day deficit
The calculator handles this automatically and also checks for very low intake floors.
What’s a Good Deficit for Most People?
For many adults, a 300–600 kcal/day deficit is effective and easier to sustain. Bigger deficits can work short-term, but often increase hunger, fatigue, workout performance drop, and rebound eating risk.
- Gentle pace: easier adherence, lower stress
- Moderate pace: good balance of speed and sustainability
- Aggressive pace: usually best for shorter phases and higher starting body fat
Practical Tips to Make Your Deficit Work
Prioritize protein
Protein helps preserve lean mass during weight loss and improves satiety. Aim for a protein intake that supports your training and body composition goals.
Use high-volume, lower-calorie foods
Vegetables, fruits, potatoes, legumes, lean proteins, and broth-based meals can help you stay full while keeping calories under control.
Keep activity steady
Daily steps and regular resistance training make your deficit more effective and help protect muscle while dieting.
Track trends, not single days
Body weight naturally fluctuates because of water, sodium, hormones, and digestion. Judge progress using weekly averages over 3–4 weeks.
Common Mistakes When Trying to Calculate Calorie Deficit
- Choosing an activity level that is too high (overestimates maintenance)
- Not weighing or portioning calorie-dense foods
- Ignoring weekend overeating that cancels weekday deficits
- Cutting calories too hard and burning out
- Changing the plan too quickly before enough data is collected
When to Adjust Calories
If your average body weight is not dropping after 2–3 consistent weeks, reduce intake by about 100–200 kcal/day or increase activity slightly. If you are losing too fast, feeling exhausted, or your training quality crashes, increase calories modestly.