Shower Cost Calculator
What one shower really costs in water and heating — per shower, per month and per year.
How it works
gallons = minutes × flow rate · water cost = gallons × $/gal · heating cost = gallons × kWh/gal × $/kWh · total = water + heating
A shower costs two things: the water itself and the energy to heat it. Minutes times the showerhead’s flow rate gives the gallons; the water rate turns that into a water charge, while the heating energy per gallon times your electricity rate gives the far larger heating charge. Multiplying by showers per day scales one shower up to the household’s monthly and yearly totals.
Worked example
A 10-minute shower at 2.1 gal/min uses 21 gallons. Water at $0.006/gal is about $0.13; heating at 0.2 kWh/gal and $0.15/kWh is 21 × 0.03 = $0.63 — roughly $0.76 per shower. One shower a day is about $22.68 a month and $276 a year.
Frequently asked questions
Why is heating so much bigger than the water charge?
Water is cheap by the gallon, but raising it from cold to a comfortable 40 °C takes real energy. That’s why a low-flow head and shorter showers save more on the power bill than on the water bill — every gallon you don’t use is a gallon you didn’t have to heat.
What if I heat water with gas, not electricity?
Convert your gas heater’s energy per gallon into your gas rate instead — roughly 0.017 therms per gallon for a typical tank heater, times your $/therm. Gas is usually cheaper per unit of heat than electricity, so the heating charge falls.
How do I find my real flow rate?
Time how long it takes to fill a one-gallon jug from the showerhead; 60 divided by the seconds is your gallons per minute. Heads made after 1994 are capped at 2.5 gal/min in the US, and WaterSense low-flow models run 2.0 or below.
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This calculator is for educational purposes. Double-check important results before acting on them.