Mini-Split Running Cost Calculator
Estimate ductless mini-split heating or cooling cost by zones, average input, runtime, and rate.
Calculate mini-split running cost
How this calculator works
Mini-splits modulate output, so rated maximum input is not the same as typical average power. This tool uses equivalent active-zone watts to model a representative day.
For multi-zone systems, outdoor-unit behavior is not always equal to the simple sum of indoor units. Whole-system metering is the best input when available.
One zone averaging 850 watts for 10 equivalent hours at $0.18/kWh costs about $1.53 per day.
How to get a more accurate estimate
- Use average measured watts rather than the maximum rating.
- Count only zones that are meaningfully conditioning space.
- Keep filters and outdoor coils clean and avoid obstructed airflow.
Frequently asked questions
Does a mini-split run continuously?
Variable-speed systems may run for long periods at low power, so clock time alone does not show energy use.
Can I multiply one zone by every head?
It is a planning shortcut; shared outdoor-unit performance means whole-system measurement is better.
Does this include defrost?
Only if the average input or measured energy already captures defrost operation.
Results use the values you enter and the formula shown above. Real bills can include taxes, minimum charges, tiers, time-of-use pricing, cycling losses, and other adjustments. Use a recent bill or a plug-in energy meter when accuracy matters.