Electric Heating Room Size Calculator

How to calculate what size heater for a room?

Electric Heating Design

Our simple electric heating room size guide is ideal for calculating the number of heaters required to heat one or two rooms. If you require:

  • A heating design for an entire property
  • A room size guide for an old building with poor insulation
  • A room size guide for a new build with very good insulation

We recommend you download our heating design request form once complete please email it to sales@electricpoint.com, we will respond with an accurate heating design within 14 working days. For multiple properties please send us the scale drawings along with any construction requirements. If you need any further help or guidance please give us a call on 0203 994 5470 or use our Contact Form.

Which heater type?

Storage heaters are ideal for living rooms, dining rooms, lounges, hallways, landings and offices or studies. The recommended temperature for dining rooms and living rooms is 21℃ and for offices and studies it is 18℃, for office calculations please download our heating guide. We highly recommend Dimplex Quantum Storage Heaters for maximum efficiency, our best selling storage heater is the Dimplex XLE range.

Electric radiators and panel heaters are ideal for bedrooms, also used in bathrooms, utility rooms, dining rooms, lounges, offices, studies, conservatories hallways and landings. The tables below provide the room sizes for bedrooms where the recommended temperature is 18℃ (also applicable for for office), for other room types please download our comprehensive heating guide. We highly recommend Dimplex QRAD electric radiators and Dimplex PLXE panel heaters which are our best selling models.

How to calculate what size heater for a room?

Our electric heating calculator actually works in reverse rather than measuring how fast heat accumulates in a room we measure how fast heat escapes from a room (known as heat loss) it is then possible to actually determine the right size or the number of electric heaters that will be required to heat a room. By determining the floor area, the wall construction and the number of outside walls we can determine the total number of kilowatts required to heat a room (we assume a standard ceiling height of 2.4M). If you have any variance please contact us for a design. The calculations in our tables will guide you on any direct acting heater such as a panel heater, convector heater, electric radiator or modern storage heater with an output rating.

Please select the room wall type from the options below to find the correct heating sizing table:

Living Rooms with Insulated Cavity Walls
Living Rooms with Cavity Walls
Living Rooms with Solid Walls

Bedrooms with Insulated Cavity Walls
Bedrooms with Cavity Walls
Bedrooms with Solid Walls

Kitchens with Insulated Cavity Walls
Kitchens with Cavity Walls
Kitchens with Solid Walls

Commercial Heating including Offices with Insulated Cavity Walls
Commercial Heating including Offices with Cavity Walls
Commercial Heating including Offices with Solid Walls

 

Living Rooms with Insulated Cavity Walls

  • Insulated cavity walls
  • Ceiling height of 2.4M
  • Room temperature of 21℃
Floor Area Number of Outside Walls
m2 1 2 3
12 1.12 kW 1.28 kW 1.68 kW
16 1.36 kW 1.60 kW 1.92 kW
20 1.68 kW 1.92 kW 2.32 kW
24 2.08 kW 2.32 kW 2.64 kW
28 2.16 kW 2.48 kW 2.96 kW
32 2.40 kW 2.72 kW 3.20 kW

 

Living Rooms with Cavity Walls

  • Cavity walls
  • Ceiling height of 2.4M
  • Room temperature of 21℃
Floor Area Number of Outside Walls
m2 1 2 3
12 1.60 kW 1.92 kW 2.48 kW
16 1.84 kW 2.32 kW 2.88 kW
20 2.32 kW 2.72 kW 3.44 kW
24 2.64 kW 3.12 kW 3.76 kW
28 2.96 kW 3.44 kW 4.24 kW
32 3.28 kW 3.76 kW 4.72 kW

 

Living Rooms with Solid Walls

  • Solid walls
  • Ceiling height of 2.4M
  • Room temperature of 21℃
Floor Area Number of Outside Walls
m2 1 2 3
12 1.84 kW 2.16 kW 2.88 kW
16 2.08 kW 2.48 kW 3.20 kW
20 2.64 kW 3.12 kW 3.92 kW
24 2.96 kW 3.44 kW 4.32 kW
28 3.28 kW 3.92 kW 4.80 kW
32 3.52 kW 4.32 kW 5.28 kW

 

Bedrooms with Insulated Cavity Walls

  • Insulated cavity walls
  • Ceiling height of 2.4M
  • Room temperature of 18℃
Floor Area Number of Outside Walls
m2 1 2 3
8 0.8 kW 0.9 kW 1.4 kW
12 0.8 kW 1.4 kW 1.8 kW
16 0.9 kW 1.6 kW 2.1 kW
20 1.0 kW 1.8 kW 2.4 kW
24 1.0 kW 1.9 kW 2.5 kW

 

Bedrooms with Cavity Walls

  • Cavity walls
  • Ceiling height of 2.4M
  • Room temperature of 18℃
Floor Area Number of Outside Walls
m2 1 2 3
8 0.8 kW 1.0 kW 1.4 kW
12 0.9 kW 1.4 kW 1.8 kW
16 1.0 kW 1.7 kW 2.1 kW
20 1.2 kW 2.0 kW 2.4 kW
24 1.2 kW 2.1 kW 2.5 kW

 

Bedrooms with Solid Walls

  • Solid walls
  • Ceiling height of 2.4M
  • Room temperature of 18℃
Floor Area Number of Outside Walls
m2 1 2 3
8 0.8 kW 1.3 kW 1.7 kW
12 0.9 kW 1.8 kW 2.3 kW
16 1.2 kW 2.1 kW 2.7 kW
20 1.4 kW 2.2 kW 3.1 kW
24 1.5 kW 2.3 kW 3.4 kW

 

Kitchens with Insulated Cavity Walls

 

For all kitchens with cavity wall insulation direct heating is preferred.

 

Kitchens with Cavity Walls

  • Solid walls
  • Ceiling height of 2.4M
  • Room temperature of 18℃
Floor Area Number of Outside Walls
m2 1 2 3
10 1.12 kW 1.6 kW 1.92 kW
12 1.36 kW 1.84 kW 2.32 kW
14 1.6 kW 2.08 kW 2.48 kW
16 1.68 kW 2.32 kW 2.72 kW

 

Kitchens with Solid Walls

  • Solid walls
  • Ceiling height of 2.4M
  • Room temperature of 18℃
Floor Area Number of Outside Walls
m2 1 2 3
10 1.28 kW 1.68 kW 2.32 kW
12 1.52 kW 2.16 kW 2.64 kW
14 1.68 kW 2.40 kW 2.88 kW
16 1.92 kW 2.64 kW 3.12 kW

 

Commercial Heating including Offices with Insulated Cavity Walls

  • Solid walls
  • Ceiling height of 3M
  • Minimum roof insulation 75mm
  • Room temperature of 21℃
Floor Area Number of Outside Walls
m2 1 2 3
15 1.68 kW 2.08 kW 2.64 kW
20 2.08 kW 2.56 kW 3.12 kW
25 2.40 kW 3.04 kW 3.60 kW
30 2.88 kW 3.52 kW 4.16 kW
40 3.92 kW 4.48 kW 5.36 kW
50 4.48 kW 5.28 kW 6.08 kW

 

Commercial Heating including Offices with Cavity Walls

  • Solid walls
  • Ceiling height of 3M
  • Minimum roof insulation 75mm
  • Room temperature of 21℃
Floor Area Number of Outside Walls
m2 1 2 3
15 2.00 kW 2.56 kW 3.52 kW
20 2.40 kW 3.12 kW 4.00 kW
25 2.72 kW 3.68 kW 4.56 kW
30 3.36 kW 4.24 kW 5.20 kW
40 4.40 kW 5.36 kW 6.72 kW
50 4.95 kW 6.24 kW 7.44 kW

 

Commercial Heating including Offices with Solid Walls

  • Solid walls
  • Ceiling height of 3M
  • Minimum roof insulation 75mm
  • Room temperature of 21℃
Floor Area Number of Outside Walls
m2 1 2 3
15 2.16 kW 2.96 kW 4.08 kW
20 2.64 kW 3.52 kW 4.48 kW
25 2.96 kW 4.08 kW 5.20 kW
30 3.52 kW 4.72 kW 5.84 kW
40 4.80 kW 5.92 kW 7.68 kW
50 5.28 kW 6.80 kW 8.40 kW

 

If you need further help or guidance please give our team of professionals a call on 0203 994 5470, drop us an email at sales@electricpoint.com or use our Contact Form.