A tankless heater makes hot water on demand, ends standby losses and typically lasts about twice as long as a tank.
Every price on this page is for whole-home gas tankless water heater, installed, compiled from public cost data across all 51 markets we track and refreshed for 2026.
Tankless Water Heater Cost at a Glance (2026)
| Installed cost range (all states) | $2,050–$6,800 |
|---|---|
| Typical installed cost (average state) | $3,749 |
| Typical yearly energy savings | $117 a year (state range $105–$130) |
| Simple payback at the typical cost | about 32.0 years |
| Expected lifespan | 20 years |
Where the Money Goes
| Cost part | Share | At the typical cost |
|---|---|---|
| Equipment & materials | 45% | $1,687 |
| Labor & installation | 45% | $1,687 |
| Permits & other | 10% | $375 |
What Affects the Price
- Conversion vs swap: replacing an existing tankless unit is cheapest; converting from a tank adds venting, mounting and plumbing changes.
- Gas line capacity: tankless units fire at 150,000-199,000 BTU, so many homes need the gas line upsized from 1/2 inch to 3/4 inch.
- Venting: gas tankless needs a dedicated stainless direct vent — it cannot share the old tank's flue.
- Flow rate and climate: colder incoming groundwater in northern states lowers a unit's real gallons-per-minute, sometimes forcing a bigger model.
- Electrical work: gas units need a 120V outlet for controls; whole-home electric tankless often triggers a panel upgrade.
When Tankless Water Heater Makes Sense
Tankless makes sense for households that use a lot of hot water — back-to-back showers, big tubs, multi-bath homes — because the water never runs out, and the unit lasts around 20 years versus 8-12 for a tank. It also suits homes short on space, since it mounts on a wall. The energy savings are real but modest, so buy it for longevity and endless hot water first and efficiency second.
When It Pays to Wait
Wait if a working tank has years of life left and nobody runs out of hot water — a like-for-like tank swap is far cheaper, and the dollar savings from going tankless stay modest either way (the percentage savings are biggest in low-usage homes, but so is the payback time in dollars). Also price a heat pump water heater before deciding: in many garages and basements it saves more per year than tankless for a similar installed cost.
Estimate Your Payback
Enter your own quote and savings estimate to see your simple payback:
Payback Calculator
Tankless Water Heater Cost by State
State guides for tankless water heater are on the way — new guides are published twice a day.
Figures compiled from public sources, updated October 2026. Local quotes vary — get 2–3 estimates.