Central heating cost
Central heating costs can run as little as 79p per day for a well-insulated, 1-bed flat on a mild 10°C day up to £20 or more per day for a poorly-insulated, draughty, 4-bed detached house on a frosty 0°C day. To learn more about the possibilities in between, read through NimbleFins estimates for central heating costs for different sizes of properties, below, and use our new calculator to estimate your own central heating costs.
Please use all figures in this article as a rough guide for educational purposes, as actual heating costs are highly variable and depend on a wide range of factors that are very hard to measure.
Central Heating Costs
To start with, let's consider a typical cold-weather day, when it's around 5°C outside and we're aiming for a cosy 20°C internal temperature—so a temperature difference of 15°C between inside and outside. How much would it cost to heat a home for a day?
That depends on many factors, but let's start with two big ones: home size and insulation level. Because the larger the home and the poorer the insulation, the higher the central heating costs.
NimbleFin estimates that the cost to centrally heat a home when it's 5°C outside ranges from £1.18-£2.76 for a 1-bed flat up to £5.60-£15.11 for a 4-bed detached home (with the lower-end cost estimates applying to well-insulated homes and the higher-end estimates applying to poorly-insulated homes).
See more about the data for this chart in the section on Central Heating Costs, per day.
Want to know more about heating costs for your specific type of property? In the following sections, we've estimated hourly and daily costs for four different property sizes, for both well-insulated and poorly-insulated homes. These costs reflect a home heated with a gas furnace, a gas cost of £0.0593/kWh (the Energy Price Cap for January to March 2026) and a target internal temperature of 20°C.
Central heating costs for a 1-bed flat
For a 1-bed flat that is roughly 8×6×2.5m and is set for a target internal temperature of 20°C, NimbleFins estimates a central heating cost ranging from around 3p per hour for a well-insulated property on a mild 10°C day up to 15p per hour for a poorly-insulated property on a frosty 0°C day.
| 1-Bed Flat: Central Heating Cost Estimates | Time period | 10°C external temp | 5°C external temp | 0°C external temp |
|---|---|---|---|---|
| Well insulated (k=0.3) | per hour | £0.03 | £0.05 | £0.07 |
| 24 hours | £0.79 | £1.18 | £1.58 | |
| Poorly insulated (k=0.7) | per hour | £0.08 | £0.11 | £0.15 |
| 24 hours | £1.84 | £2.76 | £3.68 |
Over 24 hours, the central heating costs for a 1-bed flat could range from £0.79 up to £3.68 or more, depending on insulation quality, the external temperature, the internal temperature, and other factors. Your actual costs will certainly vary.
The data above estimates heating costs for a 1-bed flat for both well-insulated and a poorly-insulated properties, across three different outdoor temperatures: 10°C, 5°C and 0°C. The lower the insulation quality and the lower the external temperature, the more expensive the central heating costs—surprise, surprise!
All properties are a bit different. See the sample home sizes we used and learn more about the k factor in the Methodology & Calculations section below. Note, the 'k-factor' is a measure of insulation quality, as discussed below.
Central heating costs for a 2-bed flat
For a 2-bed flat that is roughly 10×8×2.5m and is set for a target internal temperature of 20°C, NimbleFins estimates a central heating cost ranging from around 7p per hour for a well-insulated property on a mild 10°C day up to 30p per hour for a poorly-insulated property on a frosty 0°C day.
| 2-Bed Flat: Central Heating Estimates | Time period | 10°C external temp | 5°C external temp | 0°C external temp |
|---|---|---|---|---|
| Well insulated (k=0.3) | per hour | £0.07 | £0.10 | £0.13 |
| 24 hours | £1.58 | £2.37 | £3.16 | |
| Poorly insulated (k=0.7) | per hour | £0.15 | £0.22 | £0.30 |
| 24 hours | £3.56 | £5.34 | £7.12 |
Over 24 hours, the central heating costs for a 2-bed flat could range from £1.58 up to £7.12 or more, depending on insulation quality, the external temperature, the internal temperature, and other factors. Your actual costs will certainly vary.
Central heating costs for a 3-bed terrace house
For a 3-bed terrace house that is roughly 6×12×6m and is set for a target internal temperature of 20°C, NimbleFins estimates a central heating cost ranging from around 12p per hour for a well-insulated property on a mild 10°C day up to 52p per hour for a poorly-insulated property on a frosty 0°C day.
| 3-Bed Terrace: Central Heating Estimates | Time period | 10°C external temp | 5°C external temp | 0°C external temp |
|---|---|---|---|---|
| Well insulated (k=0.3) | per hour | £0.12 | £0.18 | £0.24 |
| 24 hours | £2.85 | £4.27 | £5.69 | |
| Poorly insulated (k=0.7) | per hour | £0.26 | £0.39 | £0.52 |
| 24 hours | £6.26 | £9.39 | £12.52 |
Over 24 hours, the central heating costs for a 3-bed terrace house could range from £2.85 up to £12.52 or more, depending on insulation quality, the external temperature, the internal temperature, and other factors. Your actual costs will certainly vary.
Central heating costs for a 4-bed detached house
For a 4-bed detached house that is roughly 8×12×7m and is set for a target internal temperature of 20°C, NimbleFins estimates a central heating cost ranging from around 16p per hour for a well-insulated property on a mild 10°C day up to 84p per hour for a poorly-insulated property on a frosty 0°C day.
| 4-Bed Detached: Central Heating Estimates | Time period | 10°C external temp | 5°C external temp | 0°C external temp |
|---|---|---|---|---|
| Well insulated (k=0.3) | per hour | £0.16 | £0.23 | £0.31 |
| 24 hours | £3.73 | £5.60 | £7.46 | |
| Poorly insulated (k=0.7) | per hour | £0.42 | £0.63 | £0.84 |
| 24 hours | £10.08 | £15.11 | £20.15 |
Over 24 hours, the central heating costs for a 4-bed detached house could range from £3.73 up to £20.15 or more, depending on insulation quality, the external temperature, the internal temperature, and other factors. Your actual costs will certainly vary.
Central Heating Costs, per hour
Per hour, the cost of central heating ranges from 3p to 84p, according to the house size, insulation quality and internal-external temperature difference. For example, a 1-bed flat that is well insulated costs 3p per hour to heat at 20°C, assuming it's 10°C outside. If the temperature was 0°C then the heating cost for this 1-bed flat would be around 7p/hour.
In contrast, a poorly-insulated, 4-bed, detached home could cost up to 84p/hour to heat, assuming it's just 0°C outside.
See the methodology section for information on the home dimensions we used for these sample properties.
| Central Heating Cost, per hour (goal: 20°C internal temp) | k-factor | 10°C external temp | 5°C external temp | 0°C external temp |
|---|---|---|---|---|
| Well insulated homes | ||||
| 1-bed flat | 0.3 | £0.03 | £0.05 | £0.07 |
| 2-bed flat | 0.4 | £0.07 | £0.10 | £0.13 |
| 3-bed terrace | 0.5 | £0.12 | £0.18 | £0.24 |
| 4-bed detached | 0.5 | £0.16 | £0.23 | £0.31 |
| Poorly insulated homes | ||||
| 1-bed flat | 0.7 | £0.08 | £0.11 | £0.15 |
| 2-bed flat | 0.9 | £0.15 | £0.22 | £0.30 |
| 3-bed terrace | 1.1 | £0.26 | £0.39 | £0.52 |
| 4-bed detached | 1.35 | £0.42 | £0.63 | £0.84 |
Central Heating Costs, per day
Per day, the cost of central heating ranges from 79p for a well-insulated, 1-bed flat on a 10°C day up to to £20 for a poorly-insulated, 4-bed detached house on a 0°C day.
Use the table below to see how daily central heating costs vary by property size, insulation quality and inside-outside temperature difference.
| Central Heating Cost, per day (goal: 20°C internal temp) | k-factor | 10°C external temp | 5°C external temp | 0°C external temp |
|---|---|---|---|---|
| Well insulated homes | ||||
| 1-bed flat | 0.3 | £0.79 | £1.18 | £1.58 |
| 2-bed flat | 0.4 | £1.58 | £2.37 | £3.16 |
| 3-bed terrace | 0.5 | £2.85 | £4.27 | £5.69 |
| 4-bed detached | 0.5 | £3.73 | £5.60 | £7.46 |
| Poorly insulated homes | ||||
| 1-bed flat | 0.7 | £1.84 | £2.76 | £3.68 |
| 2-bed flat | 0.9 | £3.56 | £5.34 | £7.12 |
| 3-bed terrace | 1.1 | £6.26 | £9.39 | £12.52 |
| 4-bed detached | 1.35 | £10.08 | £15.11 | £20.15 |
Calculator
Use this calculator to estimate central heating costs for your home. Use the results as a guide only, as the calculator uses back-of-the-envelope calculations to indicate costs, which will certainly vary significantly from one property to the next depending on many factors. If you're not sure what k-factor to use, see our section on that below—but it's a bit more art than science so you may need to play with that figure to see which produces the right results for your home (e.g. costs that seem in line with your gas bills—although yous gas bill may also reflect your hot water!).
We'd appreciate any comments on this calculator to make is as user-friendly as possible, so please tell us if you have any niggles or requests in the comments section at the bottom of this article. Thanks!
Central Heating Cost Calculator
Methodology
Estimating the cost of central heating with accuracy is actually very complicated, as the result depends on many factors that affect the heat loss of a room or home, such as:
- Size of space / external surface areas (e.g. wall and floor dimensions)
- Insulation quality (e.g. of walls, floors, ceilings, windows and doors)
- Temperature difference (inside vs. outside)
- Efficiency of heating system
That said, we've come up with a formula that takes into account all of those factors, in order to estimate central heating costs for homes with different sizes and insulation levels, and a range of indoor-outdoor temperature differences and heating efficiencies. In this article, we've used this formula to estimate central heating costs for different types of properties. Plus, we even turned this formula into a calculator to help you estimate central heating costs for your own home. Please keep in mind that the formula provides a rough estimate of central heating costs, and your real-life costs may (will!) vary from these estimates! Use them as a rough guide only, please.
Central Heating Cost Formula
A detailed formula for estimating the cost of central heating for a home would be quite complicated indeed, and include factors like separate insulation values for the various walls, windows, roof and floor of a property. We think that is too complicated for our needs here, and that most people won't have this information to hand anyway. So, we've simplified our formula to hopefully provide a realistic but manageable solution for estimating central heating costs.
Here is the formula we use for estimating the cost of central heating for a gas-powered home, per hour:
C = P × g / 1000
Where:
P = k × [(2.0 × (W + L) × h) + (2.0 × W × L)] × ΔT / e
And where:
- C = Cost of central heating, per hour (pence)
- P = Power required as energy input to the home (Watts)
- g = gas price per kWh (p/kWh)
- k = Insulation quality multiplier (e.g. 0.3 = excellent, 1.5 = very poor insulation)
- W = Width (m)
- L = Length (m)
- h = Total height (m)
- ΔT = Temperature difference between inside and outside (C)
- e = Efficiency of heating system (e.g. 90% for typical gas furnace)
Please note, this formula is our best guess at approximating the energy cost the heat a space given factors like dimensions, air-exchange with the outside, internal-external temperature difference, and other factors. Use the results as a guide only, as it will not be completely accurate given the complexity of the math and the high variability of properties in real life.
Estimated k-factors by property type
The k-factor is a measure of insulation quality, and will vary from home to home and is impacted by the walls, windows, roof and floor of a property. For our calculations, the k-factor will range from 0.3 for a very well insulated property with minimal exterior exposure (e.g. a modern, 1-bed flat) to 1.5 for a poorly insulated property (e.g. an older, unmodernised, detached home). Here are examples of k-factor estimates we use, by property type:
| Property Type | Reasoning | k-factor (well insulated) | k-factor (older/poorly insulated) |
|---|---|---|---|
| 1-bed flat | Minimal exterior exposure | 0.3 | 0.6-0.8 |
| 2-bed flat | Some exterior walls | 0.4 | 0.8-1.0 |
| 3-bed terrace | Front/back exposed, sides shared | 0.5 | 1.0-1.2 |
| 4-bed detached | All walls exposed | 0.5 | 1.2-1.5 |
Central Heating Energy Calculations
Below are calculations showing the energy needed per hour to heat well-insulated properties of different sizes with a 90% efficient gas furnace through a 20 degree (Celsius) indoor-outdoor temperature difference.
For example, a well-insulated 1-bed flat would require around 1.1 kW of energy to heat a home at 20 degrees when it's 0 degrees outside. A 4-bed detached house could require nearly 5X the energy, as you can see in the table below.
| Property Type | Sample Dimensions | k-factor | Calculation | Energy Needed per hour (gas furnace) |
|---|---|---|---|---|
| 1-bed flat | 8×6×2.5m | 0.3 | 0.3 × [(70) + (96)] × 20 / .9 | 1.1 kW |
| 2-bed flat | 10×8×2.5m | 0.4 | 0.4 × [(90) + (160)] × 20 / .9 | 2.2 kW |
| 3-bed terrace | 6×12×6m | 0.5 | 0.5 × [(216) + (144)] × 20 / .9 | 4 kW |
| 4-bed detached | 8×12×7m | 0.5 | 0.5 × [(280) + (192)] × 20 / .9 | 5.2 kW |
Poorly-insulated properties would require more energy to heat.
Apply a cost of kWh of gas and the duration to get a cost estimate, as we did in the charts and tables throughout this article.
Stay warm!