About KitPine
Free calculators for the numbers behind home projects: paint, tiles, concrete, timber, stairs and roofs.
Updated 19 October 2026
What KitPine is
KitPine is a collection of small calculators for home improvement and DIY. Each one answers a question you have before a trip to the DIY shop or the builders’ merchant: how many litres of paint to buy, how many boxes of tiles, how many bags of concrete, how steep a roof is or how many steps a staircase needs.
The tools load quickly, work on phones as well as computers, and do one job each.
How we build each calculator
Every calculator puts its formula on the page with a worked example, so you can check the result by hand. When a calculator relies on a figure from the real world, such as how far a litre of paint goes, the size of a sheet of plasterboard or the steepest stair the building regulations allow, we take it from the manufacturer, the standard or the regulations themselves and list it under Sources with the date we checked it.
Where products differ, the calculator shows our default and lets you enter the figure printed on your own product instead.
Everything runs in your browser
Calculations happen on your own device. What you type is never sent to us or stored by us, and there is no account to create.
Eight language versions
KitPine is available in English for the United States, the United Kingdom and Australia, and in Japanese, German, French, Spanish and Italian. A tool only appears in a language once it has been written for that market, with local units, product sizes and building rules. Until then, the US English version is listed with an EN label.
Estimates, not professional advice
The results are estimates for planning and shopping. For structural work, stairs, roofs and anything that needs planning permission or building control approval, the building regulations where you live and a qualified professional come first.
Free to use
All tools are free. Ads pay for the running costs. They are clearly labelled, kept away from buttons and results, and cannot see anything you enter in a calculator. The privacy policy explains the details.
If you spot a wrong figure or a translation that reads oddly, please get in touch.