Measured energy comparison
Normalise your measured kWh across complete jobs and compare like-for-like annual electricity costs.
The starting readings are hypothetical. Enter your own complete, comparable jobs. We calculate your inputs; we do not verify meter readings or publish them as product tests.
Reference: Ofgem GB average Direct Debit rate, 1 October–31 December 2026: 26.32p/kWh. Checked 8 November 2026. Use your own bill; regional and payment-method rates differ, and Northern Ireland has a separate market. Annual costs hold the entered rate constant; they are not a forecast. Standing charges are excluded. For time-of-use tariffs, calculate each rate's consumption separately and add the costs.
Use the same food portions, laundry load or other completed outcome. Include the same preparation, finishing and recharge boundaries. Do not compare one small task with a larger task.
Like-for-like measured energy
A: 0.500 kWh/job · B: 1.000 kWh/job
365.00 jobs per year under the entered schedule.
Annual difference: £48.03. A costs less.
A zero or tiny reading can reflect meter resolution. Repeated measurements under representative conditions are more informative than a single reading. Electricity only; excludes purchase costs and any standby outside your measured jobs. How to measure a complete job.
Uses your browser print dialog. Choose Save as PDF where available. Includes your current inputs and assumptions; nothing is uploaded.
Home Cost Wise - User-entered estimate, not a bill or product test. Rates and usage can change. Source and method: www.homecostwise.co.uk/methodology/
Worked example: Different measurement counts, same completed job
These fixed teaching inputs are separate from the editable calculator above and are not current tariff or product claims.
- Inputs
- A: 2.5kWh over five jobs. B: 4kWh over four equivalent jobs. Seven future jobs per week for 365/7 weeks.
- The working
- A: 2.5 ÷ 5 = 0.5kWh/job. B: 4 ÷ 4 = 1kWh/job. Apply the same 365 future jobs to each.
- The result
- At 25p/kWh, annual electricity is £45.63 for A and £91.25 for B. This is a hypothetical reading set, not our product testing.
Marked retailer links may earn us a commission. Offers appear only when approved source data is available.
How this calculator works
Average kWh per job = total measured kWh divided by completed jobs recorded. Annual kWh = that average ? jobs per active week ? active weeks. Both options share the same projected schedule and tariff; the measurement boundaries and completed outcomes must also match.
Cost in pounds = energy in kWh × electricity rate in pence ÷ 100. Monthly costs are annual costs divided by 12; daily costs are divided by 365. These are averages over a year. Calculations retain precision until display rounding.
Get a more useful estimate
Read our step-by-step guide to measuring appliance electricity before treating a nameplate rating as a measured average.
Start with the rate on your bill and energy information for your exact model. A plug-in energy monitor can help measure suitable plug-in appliances; follow its safety instructions and power limits. Do not apply full-power wattage for 24 hours to a cycling fridge or freezer.
What is excluded?
The day/night comparison includes the standing charges you enter; appliance-only tools exclude them. Gas, water, detergent, maintenance, discounts and purchase costs are excluded unless the tool explicitly asks for a purchase premium. Usage and tariffs can change. The reference tariff covers Great Britain and does not represent Northern Ireland or every contract.
Read our sources and assumptions →Common questions
Why divide by the number of measured jobs?
A reading across five jobs is not directly comparable with a reading across four. Dividing each total by its own count gives average kWh per recorded job before applying a shared future schedule. The jobs still need equivalent completed outcomes.
Does this verify the readings or predict every future job?
No. The inputs remain your measurements and assumptions. Differences in settings, loads, starting conditions and meter resolution affect the interpretation. Repeat representative jobs and preserve your measurement notes.