Lunia · Free tools
Calorie Deficit Calculator
Compare estimated maintenance energy with a modest chosen energy difference.
Your details
Runs entirely in your browser. Nothing you type is sent anywhere or saved.
Your result
Ready to calculate
Enter your details, then calculate to see your result here.
How this calculator works
Estimated maintenance is Mifflin-St Jeor resting energy multiplied by the selected activity factor. The chosen deficit is subtracted from maintenance. The model rejects very low outputs instead of presenting them as recommended intake.
A worked example
Body weight: 70 · Weight unit: Kilograms · Height: 170 · Length unit: Centimetres · Age in years: 30 · Sex coefficient used by the formula: Female coefficient · Activity multiplier: Moderately active (1.55×) · Daily energy difference to compare (kcal): 300
- Estimated maintenance
- 2,250 kcal/day
- Energy after chosen deficit
- 1,950 kcal/day
- Chosen energy difference
- 300 kcal/day
These are illustrative inputs, not personal recommendations.
Common questions
Is this the same as a meal plan?
No. Energy calculations do not establish nutrient adequacy, medical suitability or a sustainable eating pattern.
How should I use the result?
Adult estimates only. These models are not individual nutrition plans and are not intended for pregnancy, breastfeeding, children or medical conditions affecting energy needs. A chosen deficit does not guarantee a fixed weight change. Metabolic adaptation and changing activity affect long-term outcomes.
Sources & method references
- Mifflin et al. (1990), resting energy equationpubmed.ncbi.nlm.nih.gov (opens in a new tab)
- NIDDK Body Weight Planner and model limitationsniddk.nih.gov (opens in a new tab)
Formula-based results are estimates, not individual medical advice.