# Shower Cost Calculator

Calculate the true cost of a shower including water usage and energy to heat it. Compare electric vs gas water heaters and find ways to save on your water.

## What this calculates

Find out exactly how much each shower costs you in water and energy. This calculator factors in your shower duration, showerhead flow rate, local water rates, and the type of water heater you use to give you a complete cost breakdown per shower and per month.

## Inputs

- **Shower Duration** (minutes) — min 1, max 60 — Average shower is 8 minutes.
- **Showerhead Flow Rate** (gal/min) — min 0.5, max 8 — Standard showerheads: 2.5 GPM. Low-flow: 1.5-2.0 GPM.
- **Water Cost** ($/1000 gal) — min 0 — US average is about $6 per 1,000 gallons.
- **Water Heater Type** — options: Electric, Gas — Electric heaters use kWh; gas heaters use therms.
- **Energy Rate** ($/kWh or $/therm) — min 0 — Electric: ~$0.13/kWh. Gas: ~$1.00/therm.

## Outputs

- **Water Used** (gal) — Total water used per shower.
- **Water Cost** — formatted as currency — Cost of water alone per shower.
- **Energy Cost** — formatted as currency — Cost to heat the water per shower.
- **Total Cost Per Shower** — formatted as currency — Combined water and energy cost.
- **Monthly Cost (30 showers)** — formatted as currency — Estimated cost if you shower once per day.

## Details

The cost of a shower comes from two sources: the water itself and the energy needed to heat it. The formula works as follows:

  - Water used = Duration (min) x Flow rate (gal/min)

  - Heat energy (BTU) = Gallons x 8.34 lb/gal x 60°F temperature rise

  - Electric cost = BTU / 3,412 BTU per kWh / 0.95 efficiency x rate

  - Gas cost = BTU / 100,000 BTU per therm / 0.60 efficiency x rate

The biggest factor in shower cost is duration. Cutting your shower from 10 minutes to 5 minutes halves both water and energy usage. Switching to a low-flow showerhead (2.0 GPM or less) is the next most impactful change, saving 20-40% on water and heating costs without a noticeable difference in water pressure for most people.

On average, an 8-minute shower with a standard 2.5 GPM showerhead uses about 20 gallons of water and costs between $0.50 and $1.50 depending on local rates and heater type. Over a year, that adds up to $180-$550 per person.

## Frequently Asked Questions

**Q: How many gallons does a typical shower use?**

A: A standard showerhead uses 2.5 gallons per minute. An 8-minute shower uses about 20 gallons. Low-flow showerheads use 1.5-2.0 GPM, reducing usage to 12-16 gallons for the same duration.

**Q: Is a bath or shower cheaper?**

A: A bath typically uses 36-50 gallons of water, while a quick 5-minute shower with a low-flow head uses only 7.5-10 gallons. Showers are usually cheaper unless you take very long ones (15+ minutes with a standard showerhead).

**Q: Is electric or gas water heating cheaper?**

A: Gas water heaters are typically cheaper to operate despite being less efficient (60% vs 95%) because natural gas costs less per BTU than electricity. However, the difference varies significantly by region and local utility rates.

**Q: How much can a low-flow showerhead save?**

A: Switching from a 2.5 GPM showerhead to a 1.5 GPM model saves 40% on water and heating costs per shower. For a family of four, this can mean $200-$400 in annual savings.

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Source: https://vastcalc.com/calculators/everyday/shower-cost
Category: Everyday Life
Last updated: 2026-04-21