Replacing an existing water heater runs $500–$3,800 installed, and this calculator prices it by type and brand tier — budget, midrange or premium — rather than by type alone. Switching to tankless carries a cost the unit price does not: gas tankless commonly needs $750–$1,550 of gas-line upsizing and new venting, and electric tankless needs a $200–$600 dedicated circuit, priced as a separate line because it depends on what the home already has.
Brand tier, not just type, sets where you land in the range
This calculator asks for a brand tier because the spread inside one water heater type is nearly as wide as the spread between types. For a 50-gallon electric tank at an average-cost labor market, the module prices a budget unit at $650–$1,100 installed and a premium unit at $1,150–$1,900 — the premium floor is close to the budget ceiling.
The cost a tankless swap adds that the unit price does not include
Swapping a tank for a tankless unit is not just a pricier appliance — it is frequently a different infrastructure job, and this calculator keeps that cost as a separate figure rather than folding it into the headline total, because whether you need it at all depends on what the house already has.
| Conversion | Extra cost | Why |
|---|---|---|
| Gas tankless | $750–$1,550 | Larger gas line plus new stainless venting — the old tank's vent can't be reused |
| Electric tankless | $200–$600 | Dedicated high-amp circuit |
A full electrical panel upgrade, when one is needed, is a separate and less common case this calculator does not model.
That means a gas tankless job quoted at $950–$1,800 for the unit and labor can land at $1,700–$3,350 once the line and venting work is real rather than assumed away — and there is no way to know which case you are in without a plumber looking at the existing gas line and vent run first.
Labor market and the tax credit that no longer applies
Labor bands here are the same as installation: $150–$300 in a low-cost market, $250–$500 average, $400–$800 high. That range tracks the wage spread the Bureau of Labor Statistics reports for plumbers — a 10th-to-90th-percentile hourly range of $21.22 to $52.13, among the highest-paid trades this site tracks.
This calculator applies no federal tax credit to any result: the 25C credit for qualifying high-efficiency and heat pump water heaters ended for units placed in service after December 31, 2025. If a contractor's quote still nets out a federal credit for a 2026 install, ask them to point to the current program — state or utility rebates may still exist, but they are separate from 25C and not modeled here.
Replacing on your schedule rather than the tank's
The cheapest water heater replacement is a planned one. An emergency replacement costs more in every dimension: the call-out, the restricted choice of unit, and any water damage that prompted the call.
That argues for replacing on age and evidence rather than on failure. Rust-coloured hot water, moisture at the base, or a tank that no longer holds temperature the way it did are all signals that the decision is now rather than later — and all of them give you time to get more than one quote.
It also argues for deciding the fuel and format question before you are under pressure. Switching between tank and tankless, or between gas and electric, often requires venting, gas line or electrical work that cannot be arranged in an afternoon.
Methodology
Unit, labor and tankless-conversion figures are the literal constants in this calculator's module (src/lib/calculators/water-heater-replacement.ts) and its cost dataset. Wage figures are BLS OEWS May 2025 national profiles for Plumbers, Pipefitters and Steamfitters (SOC 47-2152). No figure is estimated or interpolated.