Water Heater Cost by Size: 40 vs 50 Gallon & More (2026)

Tank size is one of the biggest drivers of a water heater's price. Most homes use a 40 or 50 gallon tank, and Angi puts a 50-gallon replacement at $800 to $2,500 installed.

Installed cost by tank size

Tank size	Angi	HomeGuide
30 gallon	$700 – $2,100	$500 – $1,900
40 gallon	$800 – $2,300	$600 – $3,000
50 gallon	$800 – $2,500	$700 – $3,100
65 gallon	–	$900 – $3,400
75 gallon	$1,100 – $4,000	$1,100 – $3,600
80 gallon	$1,300 – $7,500	$1,200 – $4,000

Unit price by size

Tank size	Unit only (HomeGuide)
30 gallon	$300 – $900
40 gallon	$400 – $2,000
50 gallon	$500 – $2,100
65 gallon	$700 – $2,400
75 gallon	$900 – $2,600
80 gallon	$1,000 – $3,000

40 vs. 50 gallon

The price gap between a 40 and a 50 gallon tank is small in both surveys: Angi's ranges differ by $200 at the top end, and HomeGuide's by about $100. The larger tank stores more hot water for back-to-back showers. Upsizing can be limited by the space the old tank occupied, so measure the closet or alcove before choosing a bigger model.

Choosing a size

Size the tank to the household's peak demand, such as several showers in the morning plus a dishwasher. A plumber can calculate the first-hour rating you need. If you regularly run out of hot water, a tankless unit is an alternative: see tankless water heater cost.

Other costs

Size changes the unit price, but labor, permits and haul-away are similar for most sizes. Full breakdown: water heater replacement cost.

How to choose the right size

For tank water heaters, two numbers matter: the tank capacity in gallons and the first-hour rating, which is how much hot water the heater can deliver in an hour starting with a full tank. The first-hour rating is a better guide to whether a heater can keep up with your busiest hour.

Matching size to your household

Think about the busiest time of day in your home: back-to-back showers, a dishwasher and a washing machine running at once. A household with several people showering in the morning needs a higher first-hour rating than a couple, even if they use similar amounts of water over a whole day.

Bigger is not always better

A tank that is too large wastes energy keeping unused water hot, takes more floor space and costs more. A tank that is too small runs out. Gas heaters recover faster than standard electric heaters, so a gas tank of the same size can often serve more people.

Tankless sizing is different

Tankless heaters are sized by flow rate (gallons per minute) at a given temperature rise. Count the fixtures that might run at once and compare their combined flow with the unit's rating at your winter incoming water temperature.

Space and code limits

Measure the space and the door you will need to bring the heater through. Larger tanks are taller and wider, and some closets cannot fit them. Replacement installs also need room for code-required parts such as an expansion tank or drain pan.

Questions to ask

What first-hour rating do you recommend for my household?
Will a larger tank fit in my current location?
Would a heat pump or tankless model make sense for my use?

In Texas

Incoming water in Texas is warmer than in northern states for most of the year, which helps both tank and tankless heaters. Winter water is colder, so size for the coldest months.

How to estimate your household's peak demand

The most useful number when sizing a tank is not the tank capacity but the first-hour rating (FHR), printed on the yellow EnergyGuide label. It tells you how much hot water the heater can deliver in one busy hour, starting with a full tank. To find what you need, think about your busiest hour of the day, usually the morning, and add up what runs at once or back to back: showers, a dishwasher, a washing machine on a hot cycle, a kitchen sink.

A household with two people showering in the morning and nothing else running needs much less than a family of five with back-to-back showers and a load of laundry. Matching the FHR to that peak hour is more accurate than choosing a size by the number of bedrooms.

Recovery rate

Recovery rate is how fast the tank reheats water after it is used. Gas tanks generally recover faster than standard electric tanks of the same size, because the burner adds heat faster than electric elements. That is why a gas tank can sometimes serve the same household as a larger electric tank. If you are switching from gas to electric, you may need a bigger tank to get the same experience.

Tank size and space

A larger tank is taller, wider or both. Before choosing a bigger model, measure the space, including the door the tank must pass through, the height under any shelf or ceiling, and the clearance needed around a gas heater. Tall, narrow "slim" models and short "lowboy" models exist for tight spaces, but they cost more and may have lower ratings.

Energy use and standby loss

A tank keeps its water hot all day, and it loses heat through its walls even when nobody uses hot water. A bigger tank loses more. Oversizing means paying to keep more water hot than you need. If you are between two sizes, the smaller one with a good first-hour rating is often the better choice, unless your peak use is high.

Signs your current tank is too small

Showers turn cold before the last person in the morning is done.
You schedule dishwasher or laundry runs to avoid running out.
Guests visiting regularly cause hot water shortages.

If these happen often, a larger tank, a higher-recovery model, a heat pump unit or a tankless heater may be worth considering when it is time to replace.

Signs it may be too big

If you live alone or as a couple and rarely use much hot water, a large tank mostly costs you money in standby loss. Downsizing at replacement time can lower your energy bills without any change in comfort.

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Water Heater Cost by Size: 30, 40, 50 and 80 Gallon