About What Can We Afford

What is this?

What Can We Afford is a free mortgage affordability calculator built for UK home buyers. It lets you run multiple price scenarios side by side — so instead of asking "can we afford this house?", you can ask "what's the most we can comfortably afford, and where does it get tight?"

It's designed for joint applications with up to four applicants, each with their own budget and income split.

How the calculations work

Each scenario calculates:

Monthly mortgage payment — standard repayment formula based on the loan principal, interest rate, and term you enter
Monthly bills — whatever you enter in the bills panel, split across applicants by income share
Stamp Duty Land Tax — calculated using England & Northern Ireland rates, including first-time buyer relief where applicable
Per-applicant affordability — each applicant's share of total monthly cost compared to their stated maximum budget

Important disclaimer

What Can We Afford is a planning tool, not financial advice.

The figures produced are estimates based on the inputs you provide. They do not account for your full financial circumstances, credit history, lender criteria, or any other factors a mortgage lender would consider. Always consult a qualified, FCA-authorised mortgage adviser before making any financial decision.

Stamp duty

Stamp duty calculations use England and Northern Ireland (SDLT) rates. If you are buying in Scotland (Land and Buildings Transaction Tax) or Wales (Land Transaction Tax), the thresholds and rates differ — consult GOV.UK for the correct figures.

Interest rates

The calculator uses the rate you enter. Actual mortgage rates vary by lender, loan-to-value ratio, credit score, and product type. Use a rate from a mortgage in principle or a current market estimate.

Council tax

Default council tax amounts are England 2026/27 averages based on MHCLG statistics. Your actual bill will depend on your local authority and specific property band.

Your data

All data you enter stays in your browser. Nothing is sent to our servers except the numbers needed to calculate scenarios. We do not store, sell, or share your financial inputs. See our privacy policy for full details.

Contact

Questions, feedback, or bug reports: info@whatcanweafford.co.uk