UK CIS Calc is a free, single-purpose calculator: it estimates the Construction Industry Scheme (CIS) deduction a contractor takes from a subcontractor's invoice at 20%, 30% or 0%, and what the subcontractor receives.
Every rate and threshold is taken from official UK government sources and linked on the page where it is used:
Rates were last checked on 19 October 2026. When HMRC publishes new rates for a tax year, we update the calculator and the guides and change this date.
All sums run in your browser. We do not ask for your name, and we never receive the numbers you type in. The calculator takes your gross invoice, removes VAT, materials the subcontractor paid for and other allowed items, and applies the CIS rate to what is left, in the order GOV.UK describes.
This is an estimate to help you understand the rules. It is not tax, legal or financial advice, and we are not affiliated with HMRC. For decisions about your own affairs, check your official account or speak to an accountant.
UK CIS Calc is part of Alts Directories, a small UK publisher of free tools and directories. It is run from the United Kingdom by Alts Directories.
Spotted a mistake or out-of-date figure? Please tell us on the contact page and we will fix it.