Mortgage Affordability Calculator UK
This mortgage affordability calculator UK helps you estimate how much you may be able to borrow and what sort of property budget that borrowing could support. It is designed for buyers, movers and remortgagers who want a fast planning estimate before speaking to a lender or broker.
The calculator combines an income multiple approach with a stress-tested monthly payment check, so you can see a more practical borrowing estimate based on the information you enter.
What this calculator includes
- Main income, second applicant income and other provable income
- Deposit and optional target property price
- Monthly committed costs
- Mortgage term, initial rate and stress rate
- Income multiple scenarios
- Estimated borrowing amount and property budget
- Optional target-property check with estimated loan-to-value (LTV) and payments
How it works
The tool first estimates borrowing using the income multiple you choose. It then estimates a second borrowing limit based on an affordable monthly payment capacity using your housing ratio, mortgage term and stress rate. The lower of those two figures is used as the indicative mortgage affordability result.
This gives you a more realistic estimate than relying on income multiples alone, because it also tests whether the payments could still look affordable under a higher assumed rate.
Why your result may be different
Real lenders can produce different affordability outcomes because they do not all assess income and expenditure in the same way. Some may treat bonuses, overtime or commission differently, apply stricter stress testing, use different age limits, or allow different affordability models for higher earners.
- Credit commitments and existing debts
- Household spending assumptions
- Dependants and household size
- Variable income treatment
- Product-specific lender rules
Who it’s for
- First-time buyers checking their likely borrowing range
- Home movers comparing property budgets
- Couples combining incomes for a joint mortgage
- Anyone stress-testing whether a target property looks affordable
Mortgage affordability examples
- £35,000 income with a smaller deposit may support a modest borrowing range depending on commitments and term
- £60,000 joint income with low monthly commitments may support a higher borrowing estimate
- A larger deposit can increase your available property budget even when the borrowing figure stays the same
- Higher monthly commitments or a tougher stress rate can reduce what looks affordable
Important note
This calculator provides general estimates only. It does not perform a credit check, does not account for every lender rule, and does not guarantee mortgage approval. For an official assessment, speak to a lender or qualified mortgage adviser.
Use the calculator above to estimate your borrowing range, compare different assumptions and see how deposit size, commitments and stress testing affect affordability.