Calorie Deficit Calculator - Daily Calories & Timeline to Goal
Plan a sustainable calorie deficit by estimating your TDEE, choosing a daily deficit, and seeing how long it may take to reach your goal weight.
Weight Loss Plan
TDEE minus daily deficit with timeline to goal weight.
Deficit Results
Daily Calorie Target
2,075 kcal
30 weeks to goal at 1.0 lbs/week
Methodology and limitations
Last reviewed:
Methodology
Estimates TDEE via Mifflin-St Jeor BMR and activity multiplier, subtracts the entered daily deficit for target calories, and projects weeks to goal using the 3,500 kcal-per-pound approximation.
Limitations
Weight loss rate varies with metabolism, adherence, water retention, and muscle changes. Deficits above 1,000 kcal/day may be unsafe without medical supervision.
Official sources
How Calorie Deficit Is Calculated
Plan a sustainable calorie deficit by estimating your TDEE, choosing a daily deficit, and seeing how long it may take to reach your goal weight.
Method used
The calculator estimates TDEE from your stats and activity, subtracts your chosen daily calorie deficit to get target intake, and projects time to reach your goal weight using the 3,500 kcal-per-pound rule.
Daily calories = TDEE − deficit; weeks to goal ≈ (lbs to lose × 3,500) ÷ (deficit × 7)
Practical example
Someone with a 2,400 kcal TDEE who eats at a 500 kcal deficit targets 1,900 kcal per day and may lose about 1 lb per week if intake stays consistent.
- Current and goal weight
- Age, sex, height, activity level
- Daily deficit in calories (for example 500)
The result shows TDEE, daily calorie target, estimated weekly loss, and projected weeks to goal weight.
Assumptions
- One pound of fat loss requires roughly 3,500 kcal of deficit.
- TDEE is estimated, not measured in a lab.
- Deficit must be positive and less than TDEE.
What this includes
- BMR, TDEE, target calories, weight to lose, weekly loss estimate, and weeks to goal.
What this excludes
- Metabolic adaptation, muscle gain during deficit, medication effects, eating-disorder guidance, and clinical weight-loss programs.
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Frequently Asked Questions
What is a calorie deficit?
A calorie deficit means eating fewer calories than you burn. Over time, that gap forces your body to use stored energy, which typically leads to weight loss.
How much of a deficit is safe?
A 250-500 kcal daily deficit is common for gradual loss of about 0.5-1 lb per week. Larger deficits may be harder to sustain and should be discussed with a provider.
Why does the calculator use 3,500 kcal per pound?
That rule of thumb estimates that one pound of body weight equals roughly 3,500 kcal. Real loss rates vary with water, muscle, and metabolism changes.
Will my TDEE change as I lose weight?
Yes. A lighter body generally burns fewer calories. Recalculate every 10-15 lbs lost or when progress stalls to keep your plan accurate.
Can I lose weight without tracking calories?
Some people succeed with habit changes alone, but tracking provides a clear deficit target. Combine calorie awareness with protein, sleep, and activity for best results.