Cooling
Air conditioning cost
Enter the AC power draw, daily hours, cooling days, and electricity rate to estimate the monthly cost.
Monthly AC cost$39.31218 kWh used
Daily AC cost$1.51on cooling days
Yearly if repeated$471.74same usage all year
AC cost calculator for renters
Find the cheaper way to cool a rented room.
CoolBill helps renters estimate what a window, portable, or split AC could add to the monthly electricity bill before running it every night.
Monthly cooling$39.31
editableAC
Cooling calculator
Estimate AC cost from watts, hours, days, and your electricity rate.
Assumptions
Set the calculator to match the room you actually cool.
Room size matters
A small bedroom and a sunny living room can behave very differently. Use the wattage from the actual unit label when possible.
Use bill-rate math
If your bill has tiered or time-of-use pricing, start with the rate that applies during the hours you usually cool the room.
Ignore landlord promises
Use this as a neutral estimate before agreeing to split utilities, buy a portable unit, or run the AC overnight.
Renter checks
Questions to answer before running the AC all night.
- 01Window unit or portable unit?
Compare the expected monthly cost of the exact wattage printed on each unit.
- 02All night or timed cooling?
Change daily hours from 8 to 4 and see whether a timer meaningfully lowers the bill.
- 03Shared utilities?
Use the monthly estimate as a starting point for a fair roommate or landlord conversation.
Calculator guide
Estimate the cost to run an air conditioner before the next electric bill lands.
CoolBill turns AC wattage, daily runtime, cooling days, and electricity rate into a monthly cost estimate. It is built for renters, roommates, and small apartments where one window, portable, or split unit can change the bill fast.
Use it to compare running the AC all night versus using a timer, to check a secondhand unit before buying it, or to make a shared-utilities conversation less vague.
air conditioner electricity cost calculatorwindow AC monthly costportable AC running costAC cost for renters
FAQ
Common questions before using the estimate.
How much does it cost to run an air conditioner?
The cost depends on watts, hours used, days used, and your electricity rate. Higher wattage and longer runtime raise the monthly estimate quickly.
Is a portable AC cheaper to run than a window unit?
Not always. Compare the wattage and expected runtime of each unit. A lower sticker price does not guarantee a lower monthly electric cost.
Which electricity rate should I enter?
Use the per-kWh rate from your bill. If your plan has time-of-use pricing, use the rate that applies during the hours you usually cool the room.