Running Cost Calculator
What a load actually costs to run. Enter the power and the hours, and put in your own unit rate from the bill:cost = kW × hours × unit rate. Useful for justifying a change to a client, or for settling an argument about the heater in the site cabin.
Cost
Effective power--
Energy per year--
Per hour running--
Per day--
Per month--
Per year--
Duty cycle is the one people forget. A 3 kW heater on a thermostat does not draw 3 kW all day; it cycles. Running the sum at 100% when the real figure is 40% overstates the bill by two and a half times, and it is the usual reason a predicted saving never shows up.
Annual Energy & Running Cost FormulationThe Electricity Act 1989 & Retail Energy Tariffs
AM2 PORTFOLIO & DESIGN AUDIT FORMATTRANSPARENT FIRST-PRINCIPLES MATHS
Example calculation: A 3 kW heater operating 8 hours per day, 5 days per week, cycling at 100% duty, at 26p per kWh:
3 kW × 8 h = 24 kWh per day24 kWh × 26p = £6.24 per day£6.24 × 5 days × 52 weeks = £1,622.40 per year
An estimate based on the figures you enter. Real bills vary with tariff structure, time-of-use rates, VAT treatment and standing charges. Always check against an actual bill before relying on the number.