Shower Cost Calculator — Water & Energy per Shower
Find out exactly what each shower costs. Enter the duration, showerhead flow rate, water tariff, energy price, and temperatures — and see the cost broken down into water and heating, plus the annual total.
min
L/min
$/m³
$/kWh
°C
°C
/yr
Water + energy combined cost for one shower
- 1
Water volume
8 min × 9 L/min = 72 L - 2
Water cost
72 L ÷ 1000 × 3 $/m³ = $0.216 - 3
Heating energy
72 × 4.186 × 23 ÷ 3600 = 1.9256 kWhSpecific heat of water is 4.186 kJ per kg per °C; divide by 3600 to convert kJ → kWh. - 4
Energy cost
1.9256 kWh × 0.15 $/kWh = $0.2888 - 5
Total cost per shower
$0.216 + $0.2888 = 0.505
How does this calculator work?
Shower cost = (flow × minutes / 1000) × $/m³ + (flow × minutes × 4.186 × ΔT / 3600) × $/kWh. Enter your flow rate (L/min), local water and energy tariffs, and temperatures to get cost per shower and the annual total.
Formula
How this is calculated
Every shower has two separate costs: the water itself (billed per cubic metre by your utility) and the energy needed to heat that water (electricity or gas, billed per kWh). This calculator multiplies your flow rate by the shower duration to find the litres used, then divides by 1000 to convert to cubic metres and multiplies by your water tariff to get the water cost.
For the heating cost, it applies the specific-heat formula: energy (kWh) = mass × 4.186 kJ/(kg·°C) × temperature rise ÷ 3600. Cold-water temperature is typically 10–20 °C depending on climate and season; a comfortable shower is usually 37–42 °C. The energy figure assumes 100 % heating efficiency — real costs may be higher if your water heater has standby losses or is a gas boiler with flue losses.
The annual cost is simply the per-shower total multiplied by the number of showers per year. Utility prices and water tariffs vary widely by country and change over time; the defaults shown are illustrative estimates — replace them with your actual bill figures for accurate results.
Frequently asked questions
A typical showerhead runs at 8–10 L/min; a water-saving head at around 6 L/min. An 8-minute shower at 9 L/min uses about 72 litres (0.072 m³). Cutting the duration in half or switching to a low-flow head cuts both water and heating costs by roughly half.
Heating cold water from ~15 °C to ~38 °C takes roughly 0.027 kWh per litre. Even at moderate electricity prices this often exceeds the typical water tariff. In countries with high electricity rates or where water heating is electric, the energy share can be 3–5× the water charge.
Reducing duration from 8 min to 5 min saves about 38 % of the total cost. Dropping the temperature from 40 °C to 37 °C reduces the heating energy by about 12 %, all else being equal. Combining both changes together can cut annual shower costs substantially.
TG we-Calculate Editorial Team. (2026). Shower Cost Calculator — Water & Energy per Shower [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/shower-cost-calculator
TG we-Calculate Editorial Team. "Shower Cost Calculator — Water & Energy per Shower." TG we-Calculate. 2026. https://we-calculate.com/calculator/shower-cost-calculator.
TG we-Calculate Editorial Team, "Shower Cost Calculator — Water & Energy per Shower," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/shower-cost-calculator
@misc{wecalculate_shower_cost_calculator, title = {Shower Cost Calculator — Water & Energy per Shower}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/shower-cost-calculator}}, year = {2026}, note = {TG we-Calculate} }
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