DIY Cost Tools
Calorie Calculator
HEALTH CALCULATOR
Estimate adult maintenance calories from resting energy expenditure and an activity multiplier.
How it works
The tool estimates resting energy with Mifflin–St Jeor, multiplies it by a broad activity factor, then applies the selected planning adjustment.
Formula
Maintenance estimate = resting estimate × activity multiplier. Planning target = maintenance estimate + selected adjustment.
Worked example
For a moderately active 35-year-old male at 80 kg and 180 cm, the resting estimate is 1,755 kcal/day and maintenance is about 2,720 kcal/day.
Important limits
- Activity multipliers are rough and self-reported activity is easy to over- or underestimate.
- Energy needs vary with health, body composition, pregnancy, medications, training, and metabolism.
- Do not use this calculator to prescribe intake for children or medical conditions.
Frequently asked questions
Is a 500-calorie adjustment right for everyone?
No. It is only a comparison option. A clinician or dietitian can help set an appropriate goal.
Why can my weight stay stable at a different intake?
Food tracking, activity, water balance, and individual energy expenditure all introduce uncertainty.
Sources and review notes
Resting energy uses the published Mifflin–St Jeor equation. The output is educational and not medical nutrition advice. Last reviewed September 29, 2026.