Electricity standing charge is not added because you pay it already. Electricity has no VAT from 1 Oct 2026 to 31 Mar 2027; gas includes 5% VAT.
Formula and breakdown
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This electric boiler running cost calculator works out what an electric boiler costs to run each year, each month and each hour in the UK, on a single-rate tariff or an off-peak and peak tariff, and compares it with a gas boiler and a heat pump delivering the same heat. It uses the Ofgem price cap for 1 October to 31 December 2026 as the default prices, and every figure can be changed to your own tariff.
Quick answer: An electric boiler running cost calculator divides the heat you need by the boiler’s efficiency and multiplies by your unit rate. Example: 9,000 kWh of heat a year at 99% efficiency and 26.32p per kWh costs about £2,393 a year, against about £952 for an 85% gas boiler and £790 for a heat pump with SCOP 3.
What Is an Electric Boiler Running Cost Calculator?
An electric boiler running cost calculator is a tool that converts a home’s yearly heat demand into the electricity an electric boiler uses and what that electricity costs. In plain words: electricity used equals heat needed divided by efficiency, and cost equals electricity used times the price per kWh. On a two-rate tariff, the price is a blend of the off-peak and peak rates weighted by how much of the boiler’s use falls in each period.
An electric boiler turns almost all the electricity it uses into heat, so the cost per kWh of heat is close to the electricity unit rate. A gas boiler burns cheaper fuel with some losses, and a heat pump moves several units of heat for each unit of electricity, which is why the three options cost so differently for the same warmth.
How Do You Use the Electric Boiler Running Cost Calculator?
- Choose a single-rate tariff, or an off-peak and peak tariff such as Economy 7.
- Enter the heat your home needs each year for heating and hot water. If you have gas bills, multiply the gas kWh by your gas boiler’s efficiency.
- Enter the electric boiler’s efficiency and its rating in kW from the datasheet.
- Enter your electricity unit rate, or the off-peak rate, peak rate and the share of boiler use that falls in off-peak hours.
- Check the gas price, gas standing charge, gas boiler efficiency and heat pump SCOP for the comparison, then read the yearly, monthly and hourly costs.
How Much Does an Electric Boiler Cost to Run per Year?
An electric boiler costs about £2,393 a year to supply 9,000 kWh of heat at the October to December 2026 price cap rate of 26.32p per kWh, or about 26.6p for each kWh of heat. The Ofgem price cap announcement sets electricity at 26.32p per kWh with a 54.83p daily standing charge and gas at 7.97p per kWh with a 29.68p daily standing charge, paying by direct debit.
| Heat needed a year (example) | Electric boiler, 99% | Gas boiler, 85%, with standing charge | Heat pump, SCOP 3 |
|---|---|---|---|
| 4,000 kWh (small flat) | £1,063 | £483 | £351 |
| 9,000 kWh | £2,393 | £952 | £790 |
| 14,000 kWh (larger house) | £3,722 | £1,421 | £1,228 |
The electric and heat pump columns leave out the electricity standing charge because a home pays it anyway. The gas column includes the gas standing charge, which you would stop paying if you removed the gas supply entirely; set it to 0 in the electric boiler running cost calculator if you keep gas for cooking. Ofgem says VAT is removed from electricity bills from 1 October 2026 to 31 March 2027, while the gas price includes VAT.
Is an Electric Boiler Cheaper on Economy 7?
Only if most of its heat is used in the off-peak hours, which a direct electric boiler rarely manages because homes need heat in the morning and evening. With an example 13p off-peak rate and 33p peak rate, the blended price only beats the 26.32p single rate once more than about 33% of the boiler’s use is off-peak.
| Share of use off-peak | Blended rate (example 13p and 33p) | Yearly cost for 9,000 kWh of heat |
|---|---|---|
| 0% | 33.0p | £3,000 |
| 40% | 25.0p | £2,273 |
| 70% | 19.0p | £1,727 |
| 90% | 15.0p | £1,364 |
High off-peak shares need a way to store heat, such as a large hot water cylinder, a thermal store or a storage boiler. Off-peak and peak rates vary by supplier and region, so replace the example rates with your own in the electric boiler running cost calculator. The Economy 7 calculator checks whether a two-rate tariff suits your whole household.
Is an Electric Boiler More Expensive Than a Heat Pump?
Yes, roughly three times more for the same heat when the heat pump has a seasonal efficiency of 3, because the heat pump delivers about 3 kWh of heat for each kWh of electricity while an electric boiler delivers just under 1 kWh. For 9,000 kWh of heat, that is about £2,393 against £790 a year at the same unit rate.
The Energy Saving Trust says households in England and Wales can get £7,500 towards an air source heat pump through the Boiler Upgrade Scheme, and gives a typical installed cost of around £12,000. Model the heat pump side in more detail with the heat pump running cost calculator.
How Much Does an Electric Boiler Cost per Hour?
At full power, an electric boiler costs its rating in kW times the unit rate: a 12 kW boiler at 26.32p per kWh costs about £3.16 an hour. In practice it cycles on and off under the thermostat, so the yearly figure from heat demand is more reliable than multiplying the hourly figure by hours of use. For a single heater or appliance, the electricity cost calculator gives the same hourly sum.
A 12 kW electric boiler draws about 52 A at 230 V, since current equals power divided by voltage, which is a large load for a home supply. It needs a dedicated circuit designed and installed by a qualified electrician to BS 7671, notifiable under Part P in England and Wales, and the electrician should check that the supply and consumer unit can take it. Removing an old gas boiler or capping the gas supply is gas work for a Gas Safe registered engineer.
Worked Example: Two-Bedroom Flat Without Gas
Example: a two-bedroom flat in Glasgow with no gas supply needs 4,000 kWh of heat a year for heating and hot water and is choosing between an electric boiler on a single-rate tariff and a heat pump. The electric boiler is rated 99% efficient.
- Electricity used: 4,000 / 0.99 = 4,040 kWh.
- Yearly cost: 4,040 x 26.32p = £1,063, about £89 a month.
- Heat pump at SCOP 3: 4,000 / 3 = 1,333 kWh x 26.32p = £351.
- Difference: the heat pump would save about £713 a year at these prices, before any installation cost.
Entering these figures in the electric boiler running cost calculator gives the same results. With no gas supply, the gas row only matters if a gas connection were added.
Frequently Asked Questions
How do I work out my heat demand for an electric boiler?
Take your yearly gas use in kWh from bills and multiply it by your current boiler’s efficiency. Example: 10,588 kWh of gas at 85% gives about 9,000 kWh of heat. Without bills, use an energy assessment or treat the figure as an example and test a range.
Are electric boilers 100% efficient?
Close to it at the point of use: nearly all the electricity becomes heat in the water. Use the efficiency on the manufacturer’s datasheet. This calculator uses 99% as an example. Efficiency does not make them cheap, because electricity costs more than three times as much per kWh as gas under the current cap.
How much does an electric boiler cost to run per month?
Divide the yearly cost by 12 for an average, but winter months cost much more than summer. Example: 9,000 kWh of heat a year at 26.32p per kWh is about £2,393 a year, an average of £199 a month.
Is an electric boiler cheaper than a gas boiler?
Not to run at current prices. With electricity at 26.32p and gas at 7.97p per kWh, an electric boiler costs about 2.5 times as much as an 85% efficient gas boiler for the same heat, even after counting the gas standing charge you would no longer pay.
Does the electric boiler running cost calculator include standing charges?
It leaves out the electricity standing charge because you pay it whether or not you use an electric boiler. It includes the gas standing charge in the gas comparison, because removing gas altogether saves it. Set that charge to 0 if you would keep gas for cooking.
Can I install an electric boiler myself?
No. An electric boiler draws a large current, about 52 A for a 12 kW model at 230 V, so it needs a dedicated circuit designed and installed by a qualified electrician to BS 7671 and notified under Part P in England and Wales. Disconnecting a gas boiler must be done by a Gas Safe registered engineer.
Checked October 2026 by the Solaxyra Editorial Team. Sources: Ofgem: energy price cap 1 October to 31 December 2026, Energy Saving Trust: air source heat pumps, HSE: domestic gas safety FAQs, Wikipedia: Electric power.