Stress test
Quick checks to reduce “surprise” scenarios: interest rate changes and temporary one-income periods.
Rate rises
See monthly impact at +1% and +2%.
If your mortgage rate is variable (or you refinance), higher rates can change the monthly payment substantially.
The calculator shows “total housing cost” at +1% and +2% APR so you can gauge affordability.
One-income resilience
What if only one person earns?
A simple test: if either person had to cover 100% of housing for a while, would there still be money left for essentials?
Tip: If the one-income leftover is negative, consider reducing the house price, increasing deposit, lowering other shared costs, or building a larger emergency fund.
Related guides
Mortgage & bills split calculator
Run your numbers live and share a scenario link.
How much house can we afford (and still save)?
Affordability framing using leftovers + a savings goal.
How much deposit do we need as a couple?
Compare deposit sizes and see how they change payments and resilience.
Can we afford a house if one income stops?
A resilience check using shared costs and stress tests.
Stamp Duty (SDLT) calculator for couples
Standard vs first-time buyer relief + surcharges.
75/25 bills split guide
For very different incomes: keep leftovers and resilience in view.
Should we split the mortgage 50/50?
A simple decision framework using leftovers and stress tests.
Partner earns more — what split is fair?
Proportional vs 50/50 vs custom, explained without judgement.
How to budget maintenance costs
Why a buffer matters and how it changes monthly affordability.
One paid a bigger deposit — how to split?
Separate ownership from monthly affordability, then agree a rule.
Tip: open a guide in one tab and the calculator in another to compare options quickly.