Water Heater Cost by Size Calculator
A bigger tank costs a bit more to buy and about the same to install. Price a 40, 50 or 75-gallon job from your numbers — and size it right first.
1 Enter your numbers
A bigger tank costs a bit more to buy and about the same to install — this 50-gallon job comes to about $1,540. Size it right with the sizing tools; don’t just buy the biggest.
Tank size shifts the price less than people expect. Going from a 40 to a 75-gallon storage tank raises the unit cost modestly and leaves the install labor roughly the same — the plumber does about the same work whichever tank they set. So the honest headline is: buy the size you actually need, not the biggest one “to be safe,” because oversizing costs you upfront and every year in standby loss.
“The size you need” is not a guess — it is the First-Hour Rating that covers your busiest hour of hot water. Settle that with what size do I need or the size-by-household tool, then come here to price the job.
Formula
total = (unit + labor + add‑ons) × (1 + contingency), for your chosen tank size
Size mainly moves the unit line; the labor and add-ons stay close. Enter your own prices — the tool holds no size-by-price table, which is what keeps it correct over time.
Worked example
A 50-gallon tank, priced from a quote:
- Unit / appliance: $750
- Labor: $550
- Add-ons: $100
Subtotal = 750 + 550 + 100 = $1,400. With a 10% contingency: 1,400 × 1.10 = $1,540. Step up to 75 gallons and mostly the unit line rises — the labor barely moves, which is why buying one size too big is a poor way to spend money.
Size first, then price
- Oversizing has a running cost. A bigger tank keeps more water hot around the clock — more standby loss on the bill. Right-size it instead: first-hour rating and peak-hour demand.
- Recovery beats raw gallons. A tank with strong recovery can deliver more in the first hour than a bigger, slower one — see the recovery-time calculator.
- Tankless changes the question. There are no gallons — you size by GPM at a temperature rise. Use the tankless sizing calculator and the tankless install tool.
- Confirm on the label. The rated First-Hour Rating on the EnergyGuide sticker is the number to match, not the gallon figure alone.
Reference table
| Type | Labeled installed band | In short |
|---|---|---|
| Electric storage tank | $800–$2,000 | Cheapest unit & simplest install; higher running cost |
| Gas storage tank | $900–$2,500 | Fast recovery, lower running cost where gas is cheap |
| Gas tankless | $1,800–$4,500 | Endless flow within its GPM; high efficiency, higher upfront |
| Electric tankless | $800–$2,500 | Point-of-use or low-demand; heavy electrical draw |
| Heat-pump / hybrid | $1,500–$4,000 | Efficiency champion (UEF ~3.5); needs warm space & clearance |
Frequently asked questions
How much does a 50-gallon water heater cost installed?
From your own quoted lines — unit, labor and add-ons — a typical 50-gallon job comes to around the $1,540 in the worked example, plus or minus your local labor and any code add-ons. Enter your numbers for a figure that matches your quote.
Is a bigger water heater much more expensive?
Not dramatically. Going up a size mostly raises the unit price; the install labor stays close because the work is similar. The bigger long-run cost of oversizing is standby loss, not the purchase — so size to your need, not to the biggest tank.
What size water heater do I actually need?
Match the First-Hour Rating to your busiest hour of hot-water use, not the number of people alone. The what-size tool and the peak-hour demand calculator settle it before you price anything.
Does size change the labor cost much?
Usually no — setting a 40, 50 or 75-gallon tank is comparable work. Labor swings far more with access, a relocation or a fuel change than with gallons; the labor tool shows that.