• Home
  • Heating & Boilers
    • Air Source Heat Pumps
    • Air Source Heat Pump Running Costs Calculator
    • Gas Boiler Replacement
    • Replacement Boiler Cost Online Calculator
    • A guide to gas boiler replacement costs
    • Making The Best Of Your Boiler Warranty
    • Wood Burning Stoves
    • Boiler Flues
    • Heating Suppliers
      • Baxi Gas Boilers
      • Glow-worm Gas Boilers
      • Ideal Gas Boilers
      • Potterton Gas Boilers
      • Vaillant Gas Boilers
      • Worcester-Bosch Gas Boilers
  • Roofing
    • A Guide To Roof Construction
    • Pitched roof problems
      • Overview
      • Slipped Tiles & Slates
      • Replacing Ridge Tiles
      • Roof Valleys Leaking
      • Rebedding Roof Verges
      • Dealing With Moss
      • Repointing Chimneys
      • Replacing Guttering
      • Repairing Roof Felt
      • Condensation In Roofs
      • Repairing Torching
      • Replacing A Pitched Roof
    • Replacing Guttering
    • Safe Working
    • Choosing A Roofing Company
    • Loft Conversions
  • Energy Saving
    • Average Energy Consumption Calculator – England & Wales
    • Average Energy Consumption Calculator – Scotland
    • Average Energy Consumption In The Home – How Do You Compare?
    • Energy Efficient Homes: Eco Houses, Zero Carbon Homes, Passivhaus & EnerPHit
    • Mechanical Ventilation Heat Recovery Systems (MVHR) Explained
    • Radiator Sizing Guide And BTU Calculator
  • Green Home Grants
    • Floor Insulation
      • Using Robotics for Underfloor Insulation of Suspended Timber Floors
    • DIY Floor Insulation
      • Underfloor Insulation Of Suspended Timber Floors
      • Insulating A Suspended Timber Floor From Above Floor
      • Insulating A Suspended Timber Floor From Underneath The Floor
  • Battery Storage & Solar
    • Solar PV Panels
    • Solar PV Panel Payback And Costs In 2019
    • Solar Panel & Battery Storage Calculator
    • Solar PV Panels: Example
    • Solar Water Heating Panels
    • Solar Battery Calculator: Likely Bill Savings
  • Other
    • Blog
    • News
    • Rainwater Harvesting Systems
    • Types Of Shower: The Best Shower For You
    • Fitting An Electric Shower

Great Home

Independent Advice On Improving Your Home

Simple Heat Output Calculator- BTU Calculator – Radiators And Wood Burning Stoves

Use our simple heat output calculator to calculate the energy requirement of your room (in kW and BTU). This will give you the wood burning stove output required in kW or the BTU output needed for radiators connected to gas central heating. All dimensions are in metres.

Insulation levels in houses have improved dramatically over the years so the calculator is best for houses built before 1976. In 1976 Building Regulations changed to require minimum levels of insulation and every decade they have been tightened further. For a more detailed figure based on your own house construction use the more specialist Great Home Radiator Sizing Guide And BTU Calculator (link opens in separate tab of your browser).

Heat output calculator

metres
metres
metres

Cubic metres room size
kW output needed
BTU output needed


How is the heat output calculated?

It measure (in metres) the length, width and height of the room and then multiplies these to get the volume of air in the room in cubic metres. An adjustment factor is then applied to allow for different levels of insulation. Four different adjustment factors are used:

  • 10 for an extremely draughty room with maybe 2 outside walls and windows and doors that have no double glazing
  • 15 for a reasonably insulated room with double glazing built before 1976
  • 20 for a room built between 1976 and 1995.
  • 25 for a room built after 1995.

Welcome

Jon Davies

Hi I'm Jon. This website seeks to help those searching for the basics about improving their home. It offers an independent view, trying to balance the interests of … read more

Recent Posts

  • £450 Million Boiler Upgrade Scheme Announced By Government
  • Green Home Grant Voucher Scheme Closes 31 March 2021
  • Hydrogen Heating Gets Boost In Government Green Industrial Revolution
  • Building Regulations: Current U-values for Insulation in Homes
  • Green Home Grant Voucher Scheme Live 30 September 2020

Tweets by Greathome1

* Cookie & Privacy Policy * Website Terms of Use * Contact Us
Copyright © 2022 Great Home