United Kingdom · GBP
Cost to Boil a Kettle Calculator UK
See the electricity cost of one boil in pence. Enter your kettle's power and actual boiling time, or use measured energy. Add your daily routine to estimate annual cost, then compare another fill or kettle.
Your kettle estimate
Start with one boil. Daily and annual totals need your schedule; comparing a second routine is optional. Inputs stay in this browser.
The example compares steady 3,000W for 4 versus 2 minutes, each four times a day for 365 days. It keeps your electricity price. The times do not imply a water volume or guaranteed saving.
How to calculate the cost of a boil
Timed energy in kWh = watts × total seconds ÷ 3,600,000. Total seconds = minutes × 60 + seconds. Multiply kWh by pence per kWh for cost in pence; divide pence by 100 for pounds.
For a kettle with automatic shut-off, time from switch-on to switch-off. The watts-and-time method assumes the entered power continues throughout that period. Rated input is an estimate if actual draw changes. A complete kWh measurement can capture variable draw directly.
Using a meter reading
For a cumulative meter, subtract the starting reading from the ending reading. Record how many complete boils the difference covers, then divide total kWh by that number. Several boils can give a more useful reading when one boil is small relative to the display's precision. Keep the water-heating routine consistent if you want to compare two fills.
Check the sample's boundaries. If it includes keep-warm or standby, that energy is allocated across the counted boils. Do not add it again. A sample with a long standby interval may not represent a routine with short gaps between boils. Daily boil frequency is a separate input from the number of boils recorded.
Comparing fills and different kettles
The Energy Saving Trust recommends avoiding unnecessary overfilling. Follow your own kettle's minimum and maximum fill instructions. The checked Morphy Richards Equip manual refers to a minimum line inside the kettle and a maximum line on the gauge; it does not establish one minimum volume for all kettles.
Compare the same required drinks at a comparable finished temperature, including every additional batch. A short boil that makes fewer drinks is not automatically a cheaper daily routine. Starting temperature, actual water volume, heat losses and shut-off behaviour can change the energy needed. This tool does not convert cups or litres into an assumed universal boiling cost.
How much does a 3kW kettle cost to boil?
These steady-power examples use the dated 26.32p/kWh GB Direct Debit, single-rate reference for 1 October–31 December 2026. They are arithmetic examples, not measured boiling times or typical consumption. Changing your calculator inputs does not change this reference table.
| Complete boil time | Energy | Electricity cost |
|---|---|---|
| 2 minutes | 0.100 kWh | 2.632p |
| 2 minutes 30 seconds | 0.125 kWh | 3.290p |
| 4 minutes | 0.200 kWh | 5.264p |
For the 2-minute-30-second example, four boils per use day over 365 days cost £48.03 per year: 0.125 kWh × 4 × 365 × £0.2632. The calculation uses the unrounded per-boil cost of £0.0329.
A cheaper boil can still give the same daily cost
As a separate invented measurement example, suppose both routines provide the same required hot drinks, but B needs more batches. A records 0.60 kWh across six boils; B records 0.36 kWh across six. At the same dated 26.32p/kWh:
| Input or result | A | B |
|---|---|---|
| Average energy per boil | 0.100 kWh | 0.060 kWh |
| Cost per boil, displayed | 2.632p | 1.579p |
| Boils per use day | 3 | 5 |
| Energy per use day | 0.300 kWh | 0.300 kWh |
| Annual cost over 200 use-days | £15.79 | £15.79 |
B costs less per boil, but both schedules use 0.30 kWh per day. Their daily and annual electricity costs are equal. The six measured boils are a sample count, not the daily frequency.
Common questions
How much does it cost to boil a kettle?
Multiply energy per boil in kWh by your rate in pence per kWh. An illustrative steady 3,000W for 2 minutes 30 seconds uses 0.125kWh and costs 3.29p at the October–December 2026 GB Direct Debit single-rate reference of 26.32p/kWh. These inputs are not measured kettle performance. Use your actual timing or energy and tariff.
How should I time a boil?
For a kettle with automatic shut-off, time from switching it on until it switches off. Enter whole minutes and seconds separately: 2 minutes 30 seconds is 150 seconds, not 2.30 minutes. The power-and-time estimate assumes the stated watts are drawn throughout that time.
Can I measure several boils together?
Yes. Enter total kWh recorded for the complete boils and how many boils the reading includes. The calculator divides energy by that count. Keep the measurement consistent: any keep-warm or standby energy included in it becomes part of that sample average. The recorded boil count is separate from the number of boils in your daily schedule.
Will boiling less water reduce my daily cost?
Compare both complete routines for the same required hot drinks at a comparable temperature. Include extra batches in each routine's daily boil count. Follow your kettle's minimum and maximum fill instructions. A lower cost per boil does not necessarily mean a lower daily cost.
Is a lower-wattage kettle cheaper to use?
Not necessarily. Lower power can mean a longer heating time. Compare total energy for the same water-heating task; wattage alone cannot establish which kettle costs less per boil. Starting water temperature, the amount heated and the finished result affect the comparison.
Which electricity rate should I enter?
Use the applicable usage rate from your bill in pence per kWh: enter 26.32 for £0.2632/kWh. The dated Ofgem reference covers Great Britain, Direct Debit and single-rate meters; Northern Ireland users should enter their own tariff. Standing charges are separate. For a time-of-use tariff, use the price for the boil or calculate different-price periods separately.
Sources and assumptions
- Energy Saving Trust: avoiding unnecessary kettle overfilling
- Morphy Richards Equip: a model-specific 3kW / 1.7L specification
- Morphy Richards Equip instructions (PDF, pages 6–7): fill limits and automatic shut-off
- Ofgem: electricity unit rates and standing charges
- Our UK calculation method and dated electricity references
Source review: 3 October 2026. No kettle was independently tested for this guide. The manufacturer specification illustrates the units; it does not supply the example boiling times. Ofgem references exclude Northern Ireland. No extra tax is added to your entered consumer price. Report a correction.