Electric water heater vs Window AC unit: which costs more to run? (2026)
Baseline uses U.S. average $0.180/kWh, typical wattage, and typical hours/day from our catalog. At that rate: Electric water heater ~$72.81/mo (405.0 kWh/mo) · Window AC unit ~$43.15/mo (240.0 kWh/mo).
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Estimates below use the rate you pick (defaults match your locale when possible). The summary paragraph above stays at U.S. average for SEO; see methodology for sources.
$0.180/kWh
Higher cost: Electric water heater · +69% ($29.66/mo vs Window AC unit)
Electric water heater
Higher cost- Typical watts
- 4500 W
- Hours/day
- 3
- Monthly est.
- $72.81
- kWh/mo
- 405.0
Window AC unit
Lower cost- Typical watts
- 1000 W
- Hours/day
- 8
- Monthly est.
- $43.15
- kWh/mo
- 240.0
Electric water heater is estimated to cost more per month at typical use.
Compare by U.S. state
State pages use local utility averages (TYPE7). Open a state for either appliance to fine-tune hours and watts.