How the calculator works
The result is a sum of line items, each with its own low and high figure. You see every line and the source it comes from, marked HG (HomeGuide, January 2026), ANGI (Angi, July 2026) or HHC (our own assumption, explained here).
Unit price. For tank heaters we use HomeGuide's price range by tank size, from $300 to $900 for a 30-gallon unit up to $1,000 to $3,000 for 80 gallons. The high end covers premium brands, power-vent models and longer warranties. For tankless we use HomeGuide's unit range of $600 to $2,600. HomeGuide does not split gas and electric tankless unit prices, so both use the same range. For heat pump water heaters HomeGuide only publishes an installed total ($2,000 to $4,600), so that line already includes labor and no separate labor line is added.
Labor. A like-for-like tank swap uses HomeGuide's $200 to $1,000. Angi reports a tighter $150 to $450 for the same job, so if your quote's labor line is at the low end of our range, that is normal, not suspicious. Tankless replacement labor is Angi's $600 to $1,900, tank-to-tankless conversion labor is HomeGuide's $600 to $2,500.
Conversions. Switching fuel or going from tank to tankless adds gas line work, venting or electrical circuits. Those lines appear only when you choose a conversion, with the source shown. For tank-to-tankless we treat HomeGuide's $600 to $2,500 conversion labor as including the new vent, because that is what the conversion labor is, and add only Angi's gas line upsizing as a separate line. Even so, the top of the range stacks the high end of every line, which real jobs rarely do; HomeGuide's installed range for tankless is $1,400 to $5,600, and most conversions land inside it.
Extras. Permit, disposal, expansion tank, relocation, vent replacement and panel upgrade are optional lines you switch on. Angi gives the panel upgrade only as "up to $2,300", so the $800 low end of that line is our own estimate.
Regional adjustment (our assumption). Neither source publishes labor by state. We apply a factor of 0.85 for below-average markets, 1.0 for an average US metro and 1.2 for high-cost markets, and only to labor lines, never to the unit price. This is a judgment based on general contractor labor rate differences, not a measured figure. If you know your local plumber rates, trust them over our factor.
Rounding. Figures are rounded to the nearest $5 below $1,000 and to the nearest $10 above.
What the quote check means
If you enter a quote, the calculator compares it with the total range for the options you selected:
- More than 20% below the low end: could be a good local price, but often a quote that leaves out the permit, haul-away or code items. Ask what is excluded.
- Inside the range: typical.
- Up to 25% above the high end: explainable by a high-cost area, a premium unit or hard access. Ask for an itemized breakdown.
- More than 25% above: get a second quote.
The check is only as good as the options you picked. If your quote includes an expansion tank and you did not tick that box, the comparison is unfair to the contractor.
What the calculator does not cover
Solar water heaters, indirect heaters fed by a boiler, commercial units and mobile home models. Angi lists solar at $1,700 to $5,500 and indirect at $1,200 to $3,500 installed, but with too little detail to split into line items, so we left them out rather than guess.