What we do
We build calculators for the questions that come up before a job: how many bags, how many tonnes, how many rolls, what size radiator, and roughly what it will cost. There are 47 of them, all free, with no sign-up.
How we work
- Every number a calculator uses, such as a bag yield, a density or a coverage rate, comes from a UK manufacturer, merchant, standard or government source. Each page lists them.
- Every result shows its working with your own measurements.
- Cost ranges come from published UK cost guides and show the date we last checked them. We review them twice a year.
- We test every formula against hand-worked examples before it goes live.
What we don't do
We don't replace a builder, surveyor, heating engineer or your council. Use our results to plan and to ask better questions, then check anything structural, gas, electrical or legal with a qualified professional.
Found a mistake? Tell us and we'll fix it.