Shower Cost Calculator
Estimate shower water volume and volume-based water cost. Enter showerhead flow, running minutes, and a price per cubic metre.
How the result changes
Only shower flow rate changes; all other inputs stay at your current values. The line illustrates the formula across the shown range. This is not a forecast of real-world outcomes.
About this calculation
A shower's water charge depends on how fast water flows and how long it runs. This calculator keeps the water volume visible and prices that volume using a water-and-sewer rate supplied by the household. Estimate shower cost when estimating personal care needs.
Formula
water litres = flow in L/min × running minutes; cost = litres ÷ 1,000 × price per m³
Worked example
With Shower flow rate: 8 L/min, Shower duration: 10 min, Water and sewer price: 4 currency units/m³, water used is 80 L.
Inputs and units
Use an actual showerhead flow rate in litres per minute where possible. Time the minutes when water is flowing, and enter a monetary rate per cubic metre; one cubic metre is 1,000 litres.
- Shower flow rate (L/min): Measure or obtain litres per minute for the actual showerhead.
- Shower duration (min): Count water-running minutes, excluding any time the tap is off.
- Water and sewer price (currency units/m³): Enter a combined volume-based rate if both charges apply.
Calculation and worked example
Multiply flow by running minutes for litres. Divide litres by 1,000 to convert to cubic metres and multiply by the entered volume-based tariff for the water-only cost In compact notation, water litres = flow in L/min × running minutes; cost = litres ÷ 1,000 × price per m³.
At 8 L/min for ten minutes, the shower uses 80 L or 0.08 m³. At 4 currency units per cubic metre, the water and sewer volume charge is 0.32 currency units.
How to use the answer
The result is the usage-based portion of a bill. Heating water can cost more than the water volume itself, and fixed service charges will not change proportionally with one shower.
Compare a shorter shower or a lower-flow head by changing one input at a time. If water is turned off during soaping, count only the running intervals for a more faithful estimate.
Assumptions and checks
Flow is constant while water runs, the tariff is linear per cubic metre, and no heating energy is included. Tiered pricing or minimum charges can make a real bill differ from the simple marginal result.
Using gallons per minute in a litres-per-minute field changes the estimated volume. Another error is multiplying 80 litres directly by a per-cubic-metre price without dividing by 1,000.
At 10 L/min for exactly one minute, output should be 10 L and 0.01 m³ before applying price. Halving running time must halve volume and variable water cost.
Common questions
What does the water used result represent?
It is the amount of water flowing through the showerhead during the entered running minutes, expressed in litres.
What should I check before relying on this result?
Confirm flow rate and tariff units; add water-heating energy and fixed utility charges separately if comparing full household costs.
Inputs
- Shower flow rate (L/min)
- Shower duration (min)
- Water and sewer price (currency units/m³)