Price one daily shower at its mixed temperature
A person’s shower delivers 40 L of mixed water at 38°C with a 13°C inlet. They estimate heat delivered to that volume, assuming negligible losses between heater and shower.
Open CalculatorInputs and calculation
| Tool input | Value |
|---|---|
| Currency | USD |
| Volume or billing unit | liters |
| Volume (L) | 40 |
| Temperature rise (°C) | 25 |
| Heating method | Electric resistance |
| Efficiency (%) | 100 |
| Energy price (USD per input kWh) | 0.25 |
| Water price (USD/L) | 0 |
Heat delivered = 40 × 25 × 0.001163 kWh. Divide by 1 to get about 1.163 input kWh. Multiply input energy by 0.25, add 40 × 0 for water, then round to USD 0.29.
Tool result · USD 0.29
| Tool input | Value |
|---|---|
| Currency | USD |
| Volume or billing unit | liters |
| Volume (L) | 1200 |
| Temperature rise (°C) | 25 |
| Heating method | Electric resistance |
| Efficiency (%) | 100 |
| Energy price (USD per input kWh) | 0.25 |
| Water price (USD/L) | 0 |
Heat delivered = 1200 × 25 × 0.001163 kWh. Divide by 1 to get about 34.89 input kWh. Multiply input energy by 0.25, add 1200 × 0 for water, then round to USD 8.72.
Tool result · USD 8.72
What the comparison shows
The monthly calculation multiplies unrounded daily energy by 30. Multiplying the displayed daily cost can introduce rounding error.
Assumptions and limits
This mixed-volume model is an energy balance. A tank may still store hotter water and draw extra energy to cover standby losses.
Related guides and examples
- What it costs to heat water
- Hot water from the tank is not the same as mixed shower volume
- Why a water heater uses energy between hot-water draws
- Two-person shower routine
- Add daily activities for a one-person home
- Convert two shower routines into monthly heated volume
- Compare shorter sessions on an electric shower