Calorie Deficit Calculator
Estimate your target calories, deficit size, weekly weight-loss rate, timeline to goal weight, and cutting macros from one simple planner.
Enter your details
What you will get
- Conservative, moderate and aggressive deficit comparison.
- Safety warnings for very low calories, aggressive rate, and low goal BMI.
- Projection chart from current weight to goal weight.
- Email result link so users can save or share the plan.
What is a calorie deficit?
A calorie deficit means your body uses more energy than you eat over time. When the deficit is sustained, body weight usually trends downward because stored energy helps cover the gap.
How this calorie deficit calculator works
The calculator first estimates your maintenance calories using your body stats, activity level and optional body fat percentage. It then compares several deficit sizes and estimates weekly weight loss using a practical energy-balance approximation.
500 calories vs percentage-based deficit
A 500-calorie deficit is simple, but it is not equally aggressive for everyone. For a person with a 2,000-calorie TDEE, 500 calories is a 25% deficit. For someone with a 3,200-calorie TDEE, it is about 16%. That is why BMITDEE shows percentage-based plans.
What is a safe calorie deficit?
A moderate deficit is usually easier to follow than an extreme one. Many users start with roughly 10–20% below maintenance and adjust after real progress data. Very low targets, rapid weekly weight loss, or a goal weight that produces an underweight BMI should be treated carefully.
How long does it take to reach goal weight?
The result page estimates your timeline from your selected deficit and the amount of weight to lose. Real results can differ because of water weight, tracking error, metabolic adaptation, changes in activity, and adherence.
What should you eat in a calorie deficit?
Calories drive the deficit, but food quality and macros affect adherence. Protein is especially important during cutting because it supports recovery and helps preserve lean mass. The result page includes cutting macro options.
Why your deficit may stop working
If weight loss stalls, your real maintenance may be lower than predicted, tracking may be inaccurate, activity may have dropped, or water weight may be hiding fat loss. After 2–4 weeks, use the TDEE Calibration Tool to estimate real maintenance from actual intake and weight change.
Helpful next steps
If your activity level is uncertain, use the Activity-Level Quiz. If formula estimates differ, use TDEE Formulas Compared. If you need macro details, read How to Calculate Macros for Cutting.
Calorie Deficit FAQ
How big should my calorie deficit be?
A 10–20% deficit is a common starting range for many adults. Larger deficits may produce faster short-term loss but can be harder to sustain.
Should I eat below BMR?
Eating below BMR can be too aggressive for many people, especially for long periods. Use safety warnings seriously and consult a qualified professional when appropriate.
Should I eat back exercise calories?
Be careful. Many trackers overestimate exercise calories. If your TDEE already includes activity, eating back all exercise calories can erase the deficit.