Important Information: For all updates and Celotex announcements since June 2017, please see the links below...  See more

Declared lambda values - Read more >

5000 Class 0 testing - Read more >

Rainscreen cladding & RS5000 - Read more >

Online Insulation U-value Calculator

The Celotex insulation U-value Calculator gives you instant access to calculating your required insulation thickness and product solution.

U-value Calculator
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The professional Celotex U-value Calculator is one of the most comprehensive online calculation services in the industry, with a variety of different insulation applications covered.

Specify your desired U-value before immediately calculating the required insulation thickness and project.

"I use the Members Area of the Celotex website on a daily basis. In particular I use the U-value Calculator within the Members Area because I can quickly produce U-value calculations for inclusion within my projects' specification" - Robin Bradbury of Bradbury Design

"Thank you for the online U-value calculator, it is really easy to use. I plan to specify Celotex from now on. It's more commonly available and easier all-round" - Jon Gay, architect from Lochaber

In order to access the Celotex U-value Calculator and download your calculation PDFs, you must register for the Members Area, which is quick and easy!

How to access and use the Celotex U-value Calculator

The following video explains how to access and step through using the online U-value calculator. 


Register now to use the Calculator Calculator Icon

Why register?

Our U-value calculator app is also available from the App Store.

If you require further help or advice on an already created U-value calculation and would like to speak with an advisor, please contact our Celotex Technical Centre on 01473 820850.

Lines are open Monday – Friday, from 8.00am – 5.15pm.

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