Electric radiator vs Tankless water heater: 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 radiator ~$48.54/mo (270.0 kWh/mo) · Tankless water heater ~$97.08/mo (540.0 kWh/mo).
Use the country selector in the tool below for your tariff and currency (defaults follow your locale, same as our appliance calculators). See methodology for sources.
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: Tankless water heater · +100% ($48.54/mo vs Electric radiator)
Electric radiator
Lower cost- Typical watts
- 1500 W
- Hours/day
- 6
- Monthly est.
- $48.54
- kWh/mo
- 270.0
Tankless water heater
Higher cost- Typical watts
- 18000 W
- Hours/day
- 1
- Monthly est.
- $97.08
- kWh/mo
- 540.0
Tankless 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.