About PropCalc UK
PropCalc UK is a free suite of UK property-investor calculators. The thesis is simple: the UK property tax and lending regime changed fundamentally between 2017 and 2026 — and most free calculators haven't caught up.
What we model that others don't
- Section 24 — the mortgage-interest restriction, baked into every yield, cash-flow and structure calculation. Including the 60%+ effective marginal band in the £100k–£125,140 personal-allowance taper zone.
- Personal vs Limited Company — full parallel models with extract / retain / hybrid extraction strategies and the crossover year your structure overtakes.
- Portfolio incorporation cost — SDLT on deemed transfer + CGT on deemed disposal + refi + ongoing overhead, with the break-even year.
- Three jurisdictions — England & NI (SDLT), Scotland (LBTT) and Wales (LTT) with the correct surcharge layers in each.
- Expat mortgages — FX haircut, lender-tier max LTV, country-risk premium, non-resident SDLT and BTL ICR re-test.
Privacy by design
All calculations run entirely in your browser. We send no data to any server. The optional Sign In is only there if you want to save scenarios across devices — it uses Firebase Authentication and Firestore, and everything else still works without an account.
Accuracy & versioning
Tax rules change every Budget. Rate tables are dated and versioned by tax year — currently May 2026 • 2026/27 tax year. The footer of every calculator surfaces the "rates as of" date so you always know how current the numbers are.
Not advice
PropCalc UK is for planning and analysis. The tax-heavy calculators (Section 24, Personal vs Company, Incorporation Cost, CGT) involve personalised circumstances and reliefs that require a qualified accountant. Use the calculator output to inform the conversation, not replace it.
Built by the team behind PropCalc.ca (Canadian property calculators). UK launch May 2026.