Free Online Insulation U-value Calculator

Our U-value calculator gives you instant access to calculating a proposed insulation thickness and product selection or giving an indicative calculation on a proposed construction detail.

U-value Calculator
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Use the calculator

Our free online U-value calculator covers a variety of different insulation applications for our Isover products.

Specify your desired U-value before immediately calculating the required insulation thickness and product selection, using our multi-application calculator.

Work through your own construction detail to get an early indication of the U-value that this might achieve.

To access the U-value insulation calculator, and download your calculation PDFs, you must log in to the Members Area, if you’re not already a member, it is quick and easy to register!


Further information

If you require further help or guidance on an already created U-value calculation or for bespoke calculations and would like to speak with an advisor, please contact our Technical Support Team at

Please note, some products in the U-value calculator may not be available from stock, or be subject to minimum order quantities and extended lead times.