Free Windows 10 ESU Cost Calculator – UK

Still running Windows 10 PCs in the business? Extended Security Updates (ESU) Year 1 ended on 13 October 2026. If you join now, you pay for Year 1 as well as Year 2, and the price doubles every year. This free spreadsheet shows what that means in pounds, and whether it's cheaper to replace the PCs.

Enter your device counts and it works out:

- the ESU cost per device and for your whole fleet, including the Year 1 back-payment Microsoft requires

- the Year 2 cost (to 12 Oct 2027) and the Year 3 cost (to 10 Oct 2028, the final year)

- ESU followed by replacement, compared with replacing now and with upgrading the PCs that can run Windows 11

- ESU as a percentage of the cost of a new PC, with a plain-English verdict

- devices used only for Windows 365 or Azure Virtual Desktop, which get ESU at no extra cost

It uses Microsoft's published prices: $61 per device in Year 1, doubling each year. Change the exchange rate, or type in your UK reseller's quote in pounds. Every Microsoft date is in one place.

Works in Excel, LibreOffice and Google Sheets. No macros. Comes with a one-page quick-start PDF.

This is a planning estimate, not licensing advice. Prices exclude VAT.