The ROCKWOOL U-value calculator is a free, online tool designed to help specifiers, selfbuilders and construction stakeholders to calculate U-values for their individual projects using ROCKWOOL stone wool insulation.

With up-to-date information on ROCKWOOL solutions and a series of BIM objects, users can quickly and easily calculate accurate U-values for walls, floors and roofs according to around 2,500 pre-determined calculations. The BIM object for each specific build-up can be downloaded in IFC format to support design and inform specification.

What is a u-value?

U-value is a measure of the rate of thermal transmittance through a structure or material, which shows how good a thermal insulator or conductor that material is.

U-values are measured in W/m2K and when it comes to insulation, low U-values indicate solutions which offer excellent thermal performance capable of reducing heat loss, improving energy efficiency and promoting indoor comfort.

Using the ROCKWOOL U-value calculator, construction stakeholders can now easily identify insulation solutions which help them meet their thermal targets, and ultimately create buildings which benefit from long-lasting energy efficiency.

How our u-value calculator works

The ROCKWOOL U-value calculator is backed up by around 2,500 pre-determined calculations which show the overall performance of a wall assembly, or floor and roof build-ups featuring ROCKWOOL insulation solutions. 

To use the U-value calculator, simply visit the tool and begin by selecting your application. Follow the on-screen prompts to enter your project details, then use the sliders to adjust insulation thickness or desired U-value – and remember to download your results. To work seamlessly across a selection of ROCKWOOL technical tools, register for an account or log in to improve the experience.

All results delivered by the ROCKWOOL U-value calculator are downloadable in IFC format for use in specification and design.


Access U-Value Calculator

Frequently asked questions

What does U-value mean?
What is a good U-value?
Is a lower U-value better?
How do you reduce a U-value?
What U-value do I need for walls?
What is a good window U-value?
What U-value do I need for floors?
What is a good U-value for floor insulation?
What is R and U-value?
What is a good U-value for a house?
What is the U-value of insulation
What does U stand for in U-value?