What you need to know
- Convert minutes to hours before multiplying by kW.
- Multiply by the number of showers and days.
- Water cost is separate from electricity cost.
Use your own measurements
BricoDato tools help turn the guide into quantities, kWh, cost or a project plan.
The basic formula
Energy per shower is heater kW × shower minutes ÷ 60. Multiply that by the electricity price to get energy cost per shower.
A short time change matters
At 7.5 kW, one extra minute is about 0.125 kWh. Across several people and every day, small time differences add up.
Water flow also matters
Electrical power affects how much water can be heated to the desired temperature. Flow rate and incoming-water temperature influence comfort.
Electrical safety is the priority
These are high-power fixed appliances. Cable size, protection, earthing and local electrical requirements are not DIY guesswork.
Final check
Before buying material or doing the work, review the assumptions and technical limits that matter for your specific product, room or installation.
- Use the rating-plate kW.
- Time a normal shower.
- Keep water cost separate.
- Have fixed high-power wiring checked by a qualified professional.
Keep a small job sheet
Record the measurements, product reference, technical values you used, date and final result. For maintenance or diagnostics, also note the conditions at the time. A short written record makes future comparisons much more reliable.
Turn the guide into a decision
Use your measurements and the manufacturer’s technical data. If the decision affects fixed electrical work, structure, hidden leaks, refrigerant systems or another safety-critical installation, consult a qualified professional.