Weight change is mostly energy balance plus consistency. This calculator estimates BMR (your baseline burn) and TDEE (maintenance calories) using the Mifflin-St Jeor formula, then shows calorie targets for common goals.
A calorie deficit calculator estimates how many fewer calories you need per day to reach a target weight by a target date.
How to Calculate Calorie Deficit
- Enter current stats and activity
- Enter goal weight and target date (or weekly loss)
- See suggested daily intake or deficit
- Avoid deficits that are too aggressive without medical guidance
- Track and adjust every few weeks
The Calorie Deficit Formula
Daily deficit ≈ (pounds to lose × 3,500) / days; compare to TDEE
Where: symbols follow the inputs and conventions used in this calculator (principal, rates, terms, or units as labeled).
Real-World Example
Losing 10 lb in 10 weeks implies ~500 kcal/day deficit from maintenance on average.
Quick Reference
- How to calculate Calorie Deficit?
- Enter current stats and activity Enter goal weight and target date (or weekly loss) See suggested daily intake or deficit Avoid deficits that are too aggressive without medical guidance Track and adjust every few weeks
- What is the formula for Calorie Deficit?
- Daily deficit ≈ (pounds to lose × 3,500) / days; compare to TDEE
- Can you give a real-world Calorie Deficit example?
- Losing 10 lb in 10 weeks implies ~500 kcal/day deficit from maintenance on average.
📊 Did You Know?
As of 2024, about 33% of US adults are obese (BMI ≥ 30) and about 31.6% are overweight. (CDC BRFSS, 2024)
How to Use This Calculator
- Enter age, gender, height, weight, and activity level.
- Review BMR and TDEE.
- Select a target (lose, maintain, or gain) and use the calorie targets as a starting point.
The Formula Explained
Mifflin-St Jeor Men: BMR = 10W + 6.25H - 5A + 5 Women: BMR = 10W + 6.25H - 5A - 161
W is weight in kg, H is height in cm, and A is age in years. TDEE multiplies BMR by an activity factor to estimate maintenance calories.
Tips & What Your Results Mean
A “500 calorie deficit” is a common starting point because it loosely corresponds to about 1 pound per week (since 1 lb of fat is often approximated as ~3,500 calories). In reality, bodies adapt—hunger changes, activity shifts, and weight loss isn’t perfectly linear.
The safest approach is usually the one you can repeat. If the -2 lb/week target feels miserable, use the -1 lb/week range or even a smaller deficit, then track trends over 2–4 weeks.
Protein and resistance training matter in a deficit because they help preserve lean mass. If you’re losing weight but also losing strength rapidly, the deficit may be too aggressive.
Finally, treat TDEE as an estimate. If weight is stable for two weeks at a given target, that target is close to maintenance for your current activity level.
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