Roof & Router

Home / Calculators

How much does a shower cost?

By Nazrul Islam. Updated October 11, 2026.

Short answer: heating energy in BTU = 8.34 × hot gallons × temperature rise. An 8-minute shower at 2.5 gpm uses 20 gallons. If 12 of those are hot and heated 65°F by an electric heater, that is about 1.9 kWh, or 34¢ at 18¢ per kWh. Add 20¢ of water at $10 per 1,000 gallons, and the shower costs about 54¢.

1. Your shower

Many showerheads have the flow rate stamped on them. Or time how long it takes to fill a 1-gallon jug.

2. Hot water assumptions

These are assumptions, not measured values. 60% hot and a 65°F rise (55°F cold water heated to 120°F) are example starting points. Colder climates and hotter showers mean higher numbers.

3. Prices and water heater

A standard electric resistance heater turns almost all of its electricity into heat, so 100% is the default. This ignores standby losses from the tank. A heat pump water heater can be well above 100%. 18¢ is close to the EIA forecast 2026 U.S. average. $10 per 1,000 gallons for water and sewer is only an example. Prices vary widely by utility, so check your bill.

4. What a shower costs

Per shower
54.3¢

20 gallons (12 hot). Water 20.0¢, heating 34.3¢.

Heating energy
1.91 kWh

6,505 BTU per shower before losses

Per year
$396.52

2 showers a day, 365 days. 14,600 gallons.

ShowerheadGallons per showerCost per showerCost per year
Standard 2.5 gpm2054.3¢$396.52
WaterSense 2.0 gpm1643.5¢$317.22
Savings with 2.0 gpm410.9¢$79.30
How this is calculated
  • Gallons per shower = flow rate × minutes. Hot gallons = gallons × hot share.
  • Heat needed (BTU) = 8.34 pounds per gallon × hot gallons × temperature rise in °F.
  • Electric: kWh = BTU ÷ 3,412 ÷ efficiency. Gas: therms = BTU ÷ 100,000 ÷ efficiency.
  • Water cost = gallons × your water and sewer price ÷ 1,000.
  • Per year = cost per shower × showers per day × 365. The savings row uses your other inputs with 2.5 and 2.0 gpm.

Where the money goes

Heating the water usually costs more than the water itself. The heating part depends on how much hot water you mix in and how cold your incoming water is. A lower flow showerhead cuts both parts at once.

Standard showerheads use 2.5 gallons per minute, according to the EPA. WaterSense labeled models must use no more than 2.0 gpm. EPA says the average family could save 2,700 gallons and more than 330 kWh a year by switching.

Worked examples

Each row is an 8-minute shower, 60% hot water, a 65°F rise and $10 per 1,000 gallons for water and sewer.

SetupPer showerPer year, 2 showers a day
2.5 gpm, electric (100%, 18¢/kWh)54¢$397
2.0 gpm, electric (100%, 18¢/kWh)43¢$317
2.5 gpm, gas (60%, $1.48/therm)36¢$263
2.0 gpm, gas (60%, $1.48/therm)29¢$211

In these examples, the 2.0 gpm head saves about $79 a year with electric heating and $53 with gas. It also saves 2,920 gallons a year at two showers a day.

Common questions

Why is gas cheaper per shower than electric?

At current U.S. average prices, a therm of gas costs much less than the same heat from electricity. A gas heater wastes more heat up the flue, but the price gap is larger than that loss.

What temperature rise should I use?

Use your water heater setting minus the temperature of your cold tap water. Cold water is colder in winter and in northern states. See our guide to the right water heater temperature setting.

Is the 60% hot water share accurate?

It is an assumption. A hotter heater setting means you mix in less hot water. If you know your mixed shower temperature, hot share ≈ (shower temp − cold temp) ÷ (heater temp − cold temp).

Does a heat pump water heater change the result?

Yes. Heat pump models move heat instead of making it, so their efficiency can be well above 100%. Enter the rating from the EnergyGuide label or spec sheet.

Where do I find my water price?

Your water bill lists a rate per 1,000 gallons, or per 100 cubic feet (748 gallons). Add any sewer charge that is based on water use.

Sources