Home energy & efficiency

Air Conditioner Cost Calculator

Estimate the running cost of a window or portable A/C unit by its BTU rating and typical daily usage.

1. Unit & Usage

Unit Size

Hours Running Per Day (actual compressor run time)

Your Electricity Rate ($/kWh)

2. Running Cost

kWh × rate

MONTHLY COST

$—

SEASONAL COST (3 summer months)

$—

Circuit note: larger window units (12,000 BTU+) often need a dedicated 20A circuit. Check your unit's nameplate amperage against our Breaker Size Calculator before plugging into a shared circuit.

Tips for lower running cost

Size the unit to the room — an oversized unit short-cycles and runs less efficiently, an undersized one runs constantly and still can't keep up.
A programmable thermostat or timer avoids cooling an empty room.
Keep the filter clean — a clogged filter makes the compressor work harder for the same cooling.