> R-Value and U-Value Insulation Calculator

Material List R-Value
No materials entered yet (see below)
GRAND TOTAL: R 0.000 1000001.000 R 0.000 1000001.000 0.0mm
Just the insulation: R 0.000 1000001.000 R 0.000 1000001.000 0.0mm


The R-Value calculator is best used as follows:

  1. Work out all the different materials and surfaces that make up the wall/ceiling or surface you want to work out the R-Values and U-Values for. Remember the horizontal or vertical orientation of the material is important to get its insulation value correct.
  2. Remember to take into account any air boundaries you may have, such as with the outside or with the inside of rooms.
  3. Select the Units of measurement you want to work in, either metric (AU,EU) or imperial (US)
  4. Enter each material or surface into the above R-Value calculator. To get the right depth of a material enter multiples of it tell you get above the required depth.
  5. Note the totals. The up/out values apply mostly to Winter conditions and the down/in values apply mostly to Summer conditions.

Remember, the values calculated here should be taken as a rough guide, as certain materials (i.e. reflective or foil insulation) the total R-Value effect cannot be calculated by straight addition of all the component R-Values.

Also remember, when considering the R-Value of insulation in a built construction, it is often hard to go back and add more insulation after the wall or structure has been built; so err on having slightly more insulation than you need than less insulation.

BTW If you create an account for yourself you can save the materials list you made and come back to them later..

Reset & do another calculation.

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This calculator is now available as a fully featured Android app, work out R-Values on the move and share - search for R Value Calculator on the Android Market. Or click here if on an Android phone.
Also available on Android is a free Green Dictionary of 800+ Eco & Green terms.

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