OverPayWise

Mortgage planning tools

Free mortgage affordability calculator

UK mortgage affordability calculator.

Estimate a possible mortgage amount and property value from applicant income, deposit, regular commitments, a mortgage multiple, and an optional stress test rate.

Estimate, not approval

Uses the lower of an income multiple and a stress-tested repayment limit after regular commitments.

Estimated property value

£348,547

Based on a mortgage amount of £308,547 plus a £40,000 deposit.

Inputs

Affordability details

Visual summary

Your estimate

Estimated property value

£348,547

Mortgage amount

£308,547

Deposit

£40,000

Deposit share

11.5%

LTV (loan-to-value)

88.5%

The stress-tested monthly repayment limit is the binding limit in this estimate. Assumes a 35% gross-income repayment threshold after monthly commitments. This is an estimate, not a lender decision in principle or mortgage offer.

Result interpretation

What your affordability estimate may suggest

What it means
This may suggest an estimated upper property value from the income, deposit, commitments, expenses, and stress-test assumptions entered.
Number that matters most
The estimated mortgage amount is the key figure because it shows the possible borrowing before adding your deposit to estimate a property value.
Be careful about
This is not a lender decision. Credit history, dependants, spending patterns, fees, property type, and lender criteria can change affordability.
Explore next
You may want to compare stamp duty, buying costs, LTV bands, and mortgage deals before treating the property value estimate as realistic.

Use these numbers next

Carry this estimate into the next step.

Use these planning figures when you move on to buying costs and mortgage deal comparisons. They are estimates, not a lender decision.

Continue to buying costs
Estimated property value
£348,547
Use this as the property value when checking stamp duty and other buying costs.
Estimated mortgage amount
£308,547
Use this as the mortgage amount when comparing mortgage deals.
Deposit
£40,000
Keep this visible because buying costs may reduce the deposit available.

Confidence check

First-time buyer confidence checklist

Use this checklist to spot planning gaps before you move from calculator estimates to conversations with lenders, brokers, or conveyancers. This is educational only and is not financial advice.

  • Have you allowed for a cash buffer?

    Keep emergency savings separate from the deposit and completion costs before treating a purchase budget as comfortable.

    Review buying costs
  • Have you considered moving costs?

    Budget for removals, legal work, surveys, mortgage fees, insurance, utilities, and immediate setup costs after completion.

    Check upfront cost maths
  • Do you need an Agreement in Principle?

    An Agreement in Principle can help you understand whether a lender may consider your application before you make an offer.

    Plan your mortgage steps
  • Have you checked lender eligibility?

    Income, credit history, deposit source, employment type, property type, and existing commitments can all affect lender decisions.

    Understand affordability
  • Are your assumptions realistic?

    Sense-check the property value, deposit, mortgage amount, rate, fees, term, and monthly payment against current quotes before relying on the estimate.

    Review comparison assumptions

Assumptions

Affordability estimate assumptions

Check these inputs before relying on the result.

Gross annual income
£80,000
Combined applicant income before tax, using the values entered.
Deposit
£40,000
Cash deposit entered before wider buying costs and cash-buffer decisions.
Mortgage multiple
4.5x income
One affordability limit. Individual lenders may use lower or higher multiples.
Stress-test rate
6.50%
Used to estimate whether the monthly payment might look manageable under the chosen stress assumption.
Mortgage term
25 years
Used for the stress-tested repayment estimate, not a lender offer.
Buying costs
Not deducted
Use the next step, the Stamp Duty Calculator, to estimate SDLT and wider upfront costs.

Last reviewed

12 June 2026

Interest method

Monthly interest is estimated from the annual rate unless a page states a different method. Lender figures can use daily interest, product-specific rules, and exact payment dates.

Educational scope

UK-focused calculator estimate. It explains trade-offs and does not make a personal recommendation.

How this affordability estimate is calculated
  1. Applicant income is multiplied by the mortgage multiple entered.
  2. A separate repayment check estimates a monthly mortgage payment using the stress-test rate and term.
  3. Regular commitments and essential expenses reduce the repayment capacity used in the stress-tested estimate.
  4. The calculator uses the lower of the income-multiple estimate and the stress-tested repayment estimate.
  5. The deposit is then added to the estimated mortgage amount to estimate a possible property value.

Learn the mortgage maths behind these estimates →

Main limitations
  • This is not a decision in principle, agreement in principle, credit check, or lender affordability assessment.
  • Lenders can use different income rules, stress rates, spending assumptions, credit criteria, property rules, and deposit-source checks.
  • Stamp duty, legal fees, survey costs, moving costs, product fees, insurance, and cash buffer needs are not deducted from the deposit in this estimate.

Results are estimates based on the assumptions shown here. They are not financial advice and can differ from lender figures because real products, fees, rate changes, overpayment rules, and repayment timing vary.

Learn the affordability maths

Understand borrowing power, affordability, deposit and LTV

Follow a beginner-friendly lesson covering income multiples, stress-tested borrowing limits, deposit impact, LTV, worked examples, and practice questions.

Open the affordability lesson

Key terms

Mortgage amount, property value, deposit and LTV

Mortgage amount
The estimated amount borrowed from a lender for the purchase. Lenders may also call this borrowing, but this journey uses mortgage amount for consistency.
Property value
The home price or value used in the calculator. For a first-time buyer, this usually means the planned property value.
Deposit
The buyer cash going into the purchase. Buying costs can reduce the deposit available for the mortgage application.
LTV
Loan-to-value: the mortgage amount divided by the property value. A lower LTV usually means a larger deposit share.

Calculation details

What shaped this estimate

Income multiple limit

£360,000

Based on 4.5x household gross income of £80,000.

Stress-tested borrowing limit

£308,547

Based on a maximum payment of £2,083 per month after commitments and essential expenses at 6.5% over 25 years.

Basic monthly repayment

£2,083

Estimated repayment on the mortgage amount at the stress test rate. It excludes fees, insurance, and future rate changes.

FAQ

Mortgage affordability questions

Is this mortgage affordability result an approval?

No. It is an estimate based on the income, deposit, commitments, income multiple, term, and stress rate you enter. A lender can assess credit history, spending, dependants, property type, deposit source, and its own policy before making a decision.

Why does the calculator use a mortgage multiple?

A multiple such as 4.5x annual gross income is a simple way to estimate a possible borrowing ceiling. Some lenders may use higher or lower multiples depending on income, risk, loan-to-value, and wider affordability checks.

What should I include as monthly commitments?

Include regular debt and credit commitments such as loans, car finance, credit card repayments, student loan deductions, maintenance payments, and any other recurring payments a lender may consider.

What does the stress test interest rate do?

The stress test rate estimates whether the mortgage payment may still fit within a basic repayment threshold if rates are higher. Setting it to zero removes that repayment-based cap and leaves the income multiple as the main limit.

Recommended next steps

What to check next

A short follow-up can help put this estimate into context before you make a money decision.

Important disclaimer

This calculator provides estimates only and does not constitute mortgage advice, financial advice, a decision in principle, or a guarantee that a lender will approve the borrowing. Lender affordability checks can vary significantly and may include credit history, dependants, spending patterns, stress testing, fees, deposit source, property type, and local lending rules.

Review the OverPayWise methodology and editorial standards

Learn This Calculation

Understand the lesson behind Mortgage Affordability Calculator.

Use the education page before relying on the result. It explains the assumptions, shows the maths, gives worked examples, and includes practice questions so the estimate is easier to check.

Tutorial

Start with the affordability tutorial before treating a borrowing estimate as a budget.

Maths lesson

Covers income multiples, payment stress tests, deposit percentage, and loan-to-value.

Worked examples

Works through a two-income affordability case and shows why the monthly-payment limit can bind before the income multiple.

Practice questions

Practise finding the limiting factor and checking how a bigger deposit changes LTV.

Next Lesson

Estimate buying costs

After borrowing power, check SDLT and upfront cash before comparing mortgage products.

OverPayWise provides educational estimates only. It is not FCA authorised, does not provide regulated financial advice, and does not arrange mortgages.