Tankless vs tank water heater calculator
Answer three quick questions. See what tank, tankless, and heat pump water heaters cost to run each year in your home — side by side.
How the tankless vs tank calculator works
The calculator estimates your household's yearly hot-water energy from how many people live with you, then prices delivering that hot water through each option — tank, tankless, and heat pump — using typical efficiencies (UEF for gas units, COP for electric) and your local rates. It answers the operating-cost question. For the upfront side, see the full tankless vs tank comparison and the heat pump water heater cost guide.
Everything runs in your browser and nothing is stored on our servers. Planning the bigger picture — when to replace, what order to do upgrades in — lives at the water heating upgrade hub.
Tankless vs tank questions, answered
Is a tankless water heater cheaper to run than a tank?
On gas, usually yes. A typical gas tankless runs at about UEF 0.85 versus 0.62 for a standard gas tank, cutting water-heating gas use by roughly a quarter — often $50 to $80 a year for a family of three or four. On electricity the story changes: a heat pump water heater beats both, using two to three times less electricity than a resistance tank.
How much more does a tankless water heater cost than a tank?
Installed, a standard gas tank typically runs around $1,500 to $2,500, while a gas tankless lands around $3,500 to $5,000 once venting and gas-line upgrades are included. That upfront gap is why the operating savings alone rarely pay for a tankless swap — the stronger arguments are endless hot water, 20-plus-year lifespan, and space savings.
What are the pros and cons of tankless vs tank?
Tankless pros: endless hot water, lower gas use, small footprint, roughly 20-year lifespan versus 10–15 for tanks. Cons: two to three times the installed cost, a limit on simultaneous showers set by flow rate (GPM), and annual descaling in hard-water areas. Tanks win on upfront cost and simplicity; tankless wins on running cost and longevity.
Is a heat pump water heater better than both?
For homes heating water with electricity, usually yes — a heat pump water heater moves heat instead of generating it, so it uses two to three times less electricity than a resistance tank and often beats gas on running cost too. The trade-offs are a higher purchase price, slower recovery, and needing a spot with enough surrounding air, like a basement or garage.