Understand your estimate
How to use this result
Sum selected always-on or standby modes across devices using average watts, their daily mode hours, quantities and use days. An optional reduced-hours scenario prices only the periods you identify as removable.
Method reviewed · Calculation methods · Evidence and source policy
Find the right inputs
Each device and source
Average W, quantity and source/assumption
An adapter rating or maximum input is not measured standby draw.
Current mode hours
Hours/day and annual use days
A working router is always-on active networking, not automatically standby.
Proposed hours and tariff
Optional hours ≤ current hours; currency/kWh
Blank proposed hours retain current use.
The calculation
Annual device kWh = watts ÷ 1,000 × mode hours/day × use days × quantity. Savings compare the entered current and proposed hours at the same draw and tariff.
A worked arithmetic example
Illustrative arithmetic: 10 W for 24 hours on 365 days uses 87.6 kWh and costs $17.52 at $0.20/kWh. Reducing that mode to 12 hours would halve this particular arithmetic quantity, if the period can actually be removed.
What the estimate can tell you
The audit describes selected device modes. Do not add them to a whole-day or whole-home reading that already contains them. Savings do not establish that switching a service off is practical or appropriate.
Questions about this calculation
Are all always-on watts wasted?
No. Networking, controls or another continuing service may be the intended task. Evaluate which mode and period can actually change.
Can I model several states of one device here?
Use non-overlapping periods, or use the shared operating-mode editor in the electricity tool to make the one-device 24-hour boundary explicit.