UK Mortgage Calculators
Free, mobile-friendly calculators for every stage of the mortgage journey — using current 2026 UK tax bands and lender rules.
Buying
Investment
- Buy-to-letMortgage cost, yield, stress test.
- BTL stress test (ICR)Lender ICR rules.
- Rental yieldGross & net yield.
- Holiday letComing soonFHL income & costs.
Existing owners
Specialist
- Self-buildStage payments & costs.
- Bridging loanShort-term finance cost.
- Let-to-buyLetting current home & buying new.
- Joint borrower sole proprietorComing soonBoost borrowing with a guarantor.
Why use Mortgage118 calculators?
Every calculator is built around current UK rules — SDLT bands, LBTT and LTT thresholds, lender stress test rates and FCA-aligned affordability multiples. Each result page shows its assumptions and the date they were last updated, so you always know exactly what's behind the number.
Important: Your home may be repossessed if you do not keep up repayments on your mortgage. Information on this page is for general guidance only and does not constitute financial advice.Always verify details directly and seek independent advice before making financial decisions.