Count oven preheat energy separately
A household bakes ten times in a month. The oven draws 2,400 W during a 15-minute preheat, then cycles during a one-hour bake. They want to price each phase once.
Open CalculatorInputs and calculation
| Tool input | Value |
|---|---|
| Currency | USD |
| Power unit | W |
| Power | 2400 |
| Hours per day | 0.25 |
| Days or equivalent sessions | 10 |
| Duty cycle (%) | 100 |
| Energy price (USD per input kWh) | 0.24 |
2400 ÷ 1,000 × 0.25 × 10 × 100% = 6 kWh. 6 × 0.24 rounds to USD 1.44.
Tool result · USD 1.44
| Tool input | Value |
|---|---|
| Currency | USD |
| Power unit | W |
| Power | 2400 |
| Hours per day | 1 |
| Days or equivalent sessions | 10 |
| Duty cycle (%) | 50 |
| Energy price (USD per input kWh) | 0.24 |
2400 ÷ 1,000 × 1 × 10 × 50% = 12 kWh. 12 × 0.24 rounds to USD 2.88.
Tool result · USD 2.88
What the comparison shows
Add the two separate runs for 18 kWh and USD 4.32. Omitting preheat would miss one third of the modeled energy.
Assumptions and limits
The bake duty assumption omits fan and idle draw. Results depend on temperature, oven insulation and how often the door opens.
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