UK Mortgage Calculators
Free, mobile-friendly calculators for every stage of the mortgage journey — using current 2026 UK tax bands and lender rules.
Reviewed by David Sampson, Founder & Director
Buying
- Stamp DutySDLT, LBTT, LTT — all variants.
- Commercial stamp dutyComing soonNon-residential SDLT on property, land & leases.
- AffordabilityHow much you can borrow.
- Credit scoreComing soonHow credit history and deposit combine.
- Large mortgageComing soonLarge and high net worth loans.
- Mortgage repaymentMonthly cost & total interest.
- Buy vs rentCompare monthly cost of owning and renting.
- First-time buyerAffordability + SDLT + deposit combined.
- Help to BuyComing soonEquity loan repayment and interest.
- Deposit savings goalHow long to save your deposit.
Investment
- Buy-to-letMortgage cost, yield, stress test.
- BTL stress test (ICR)Lender ICR rules.
- Rental yieldGross & net yield.
- HMO mortgageMaximum loan from room rents.
- HMO valuationRent-based value vs house value.
- Holiday letComing soonFHL income & costs.
- Expat mortgageComing soonPayments in sterling & your currency.
- Non-resident mortgageComing soonPayments in sterling & your currency.
- Limited company buy-to-letComing soonMaximum loan from the rent.
- Portfolio stress testComing soonRent cover across all properties.
Existing owners
Specialist
- Self-buildStage payments & costs.
- Bridging loanShort-term finance cost.
- Auction financeComing soonCost of a bridge for an auction purchase.
- Semi-commercial mortgageComing soonRepayments and rent cover on mixed-use property.
- Hotel mortgageComing soonRepayments and profit cover on a hotel or guest house.
- RefurbishmentComing soonLoan, interest and margin on a property that needs work.
- Care homeComing soonLoan, payments and interest cover on a care home.
- Let-to-buyLetting current home & buying new.
- Development financeComing soonBuild costs, GDV & loan size.
- Industrial mortgageComing soonFactory & warehouse repayments.
- Commercial mortgageComing soonRepayments & rent cover.
- Adverse credit mortgageComing soonRepayments at an example rate.
- 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.