Find the cheapest water heater that actually keeps up with your showers.
198 tankless and heat pump water heaters from 14 stores. Tankless heaters are ranked by price per GPM at a real 45 °F rise, not the box number; heat pump tanks by price per gallon. Tell the calculator who lives in your house and your ZIP code: it sizes the heater and compares what each kind costs to run.
Gas tankless
96 models · Natural gas and propane, whole-home, outdoor, portable and RV
from $160
Electric tankless
67 models · Point-of-use to 36 kW whole-house
from $120
Heat pump
35 models · Hybrid tanks using a third of the electricity, incl. 120 V plug-in
from $1,699
120 V plug-in heat pump water heaters
All plug-in models →Plug into an ordinary outlet: no new 240 V circuit, so a gas tank can be swapped for a heat pump without an electrician. Sorted by price per gallon.
$/gal is the price divided by tank capacity. Compare the first-hour rating (FHR) too: it is what decides whether a tank keeps up with your busiest hour. The sizing calculator works out the FHR your household needs and the running cost.
Best value whole-home gas tankless
All gas tankless →Sorted by price per GPM at a 45 °F rise. Newer brands like Fogatti and Camplux sit right next to Rinnai and Navien.
$/GPM is the price divided by the hot water flow the heater delivers at a 45 °F temperature rise, worked out from its gas input and UEF. "Box GPM" is the maker's own maximum, often quoted at a much smaller rise, so it is shown but not ranked on. Your rise depends on your incoming water: the sizing calculator works it out from your ZIP.
The honest GPM
A box that says "6.5 GPM" may mean at a 25 °F rise. We compute every heater's flow from its burner or element rating at the same 45 °F rise, so a $300 heater and a $1,800 heater are compared on what they deliver.
Sized for your water
Winter mains water is about 77 °F in Miami and under 40 °F in Minneapolis. The calculator uses your ZIP's inlet temperature to size a tankless heater, and your busiest hour to pick a tank's first-hour rating.
What it costs to run
Gas tank, electric tank, gas tankless, electric tankless and heat pump side by side: yearly energy, yearly cost at your rates, and ten-year cost including the cheapest heater that fits.
Camping or an outdoor shower? See portable propane water heaters and RV tankless heaters.