Home Affordability Calculator

What this calculator is, and when to reach for it

Everyone shops for houses in prices, but lenders think in loans. That mismatch is where a lot of wasted weekends come from: you view places at the top of what you believe you can afford, then discover the number a lender had in mind was never a price at all. This calculator closes the gap. It takes what your income and debts can support, adds the cash you are bringing, and gives you the figure you actually search with.

The logic is deliberately simple. A lender decides how much it will lend you, based on the share of income your commitments already consume. Your deposit is separate money that you supply. Add them and you have the price you could consider. Two people with identical salaries can be shopping a hundred thousand apart purely because one has saved longer.

Read the answer as a ceiling and not a shopping target. It is the top of what the ratios permit, before anyone has thought about maintenance, the cost of moving, or whether the payment still feels sane during a bad month. Most people who end up comfortable buy meaningfully below their ceiling, and the ones who regret a purchase almost always bought at it.

Use this page when you want a search bracket, when you are deciding whether saving another six months of deposit is worth delaying, or when you want to see how a rate change moves the price you can reach.

What the price figure does and does not include

The price shown is the estimated loan plus your deposit, and nothing else. It is not what the purchase costs you in total, because buying carries fees that never form part of the loan: legal work, valuation, searches, arrangement fees, and in many countries a purchase tax that is comfortably the largest of them.

Those costs come out of the same savings as your deposit, which creates a trap worth naming. Spending every last unit of cash on the deposit to reach a higher price can leave nothing for the fees, and the purchase stalls. Decide your buying costs first, set them aside, and treat only what remains as deposit.

The figure also assumes the property passes a lender’s valuation. If a surveyor values a home below the agreed price, most lenders will lend against the lower figure, and the difference lands on you in cash.

Where to go next

This page sits directly on top of the mortgage affordability calculator, which works out the loan itself and tells you whether income or existing debt is the binding constraint. If your debts are what is holding you back, the debt-to-income calculator shows exactly where your income is committed.

Once you have a price bracket, take the loan to the mortgage calculator for the real monthly payment including tax and insurance, and to the amortization calculator to see what the commitment looks like over its whole life rather than one month.

On the deposit side, the down payment calculator shows what different deposit levels do to the loan and the cash you need, and the loan to value calculator shows where you land against the thresholds that govern rates and mortgage insurance. The buying a home journey runs the whole sequence in order.

How the affordable price is worked out

The calculation has two halves. The first is borrowing capacity, worked out from ratios exactly as a lender would. The second is simple addition.

affordable price = affordable loan + deposit

affordable loan

the balance your income and debts support at the rate and term you entered

deposit

the cash you are contributing up front

Why the deposit is not just a discount

It is tempting to think of a deposit as money off the price, and arithmetically it is. But it does three separate jobs at once. It raises the price you can reach, because it is added on top of the loan. It lowers the loan itself, and therefore the payment and the total interest. And it improves your loan-to-value, which is what determines whether you get a lender’s better rates and whether mortgage insurance applies.

That third effect is the one people miss. A deposit that crosses a lender threshold can change the rate you are offered, and a better rate raises borrowing capacity, which raises the price again. The gains are not linear near those boundaries.

Why the rate moves the price so violently

Borrowing capacity is a payment converted back into a balance, so the rate governs how much of each payment repays the loan rather than servicing interest. At a lower rate the same affordable payment supports a materially larger balance.

This is why the price you can reach can move by a large margin between one month and the next without your income changing at all, and why quotes obtained weeks apart are not comparable. It also means the single most effective thing many buyers can do is improve the rate they are offered, usually by improving loan-to-value.

Ownership costs quietly lower the price

Property tax, insurance, and service charges are collected inside the monthly payment on most loans. They are part of the housing cost a lender measures, so every unit of them reduces the payment left for principal and interest, which reduces the loan, which reduces the price.

The effect is larger than most people expect, and it is why two identical homes in areas with different tax rates are not equally affordable to the same buyer. Enter these figures rather than leaving them blank; an estimate you have thought about beats a zero you have not.

What a ceiling cannot know

Ratios see income and debt payments. They do not see childcare, commuting, medical costs, how many people the income supports, or whether your work is steady or seasonal. Nor do they see what a house asks for after you own it: repairs, maintenance, and furnishing rooms you did not previously have.

A sound habit is to run the ceiling, then run the price you would still be relaxed about if one income paused for three months, and shop between the two.

What this page assumes

The calculator derives an affordable loan amount from user inputs, then adds the entered down payment to estimate a property price.

It is an educational estimate, not a lender approval or property valuation.

Worked examples, step by step

Take a buyer whose income and debts support an estimated loan of 354,392.24 at 6.5% over thirty years, with 70,000 saved for a deposit.

From loan to search bracket

The search bracket is around 424,000, and the deposit represents 16.5% of that price. That last figure matters: it sits below the one-fifth mark that many lenders use as a threshold, so this buyer would likely face mortgage insurance and may not be offered the best rates. Ten thousand more deposit would do more than add ten thousand to the price.

Note what happens if the buying costs have not been set aside. If legal fees, surveys, and purchase tax come to 15,000, then only 55,000 of that saving is genuinely deposit, and the honest bracket is closer to 409,000. Buyers who discover this late usually discover it after an offer has been accepted.

What another 10,000 of deposit is really worth

Raising the deposit from 70,000 to 80,000 raises the price bracket by 10,000 directly. But it also cuts the loan needed for any given house, improves loan-to-value, and may remove mortgage insurance from the monthly cost, which frees payment capacity and lifts borrowing power again.

Near a lender threshold, the last few thousand of deposit is the most valuable money in the whole transaction. Away from a threshold, it is worth roughly what it says. The loan to value calculator is the quickest way to see which side of that line you are on.

The vocabulary, on and around this page

Affordable price

The estimated loan plus your deposit. It is a search ceiling rather than a recommendation, and it excludes the costs of buying.

Affordable loan

The balance your income and existing debts could support under the ratio limits you chose, at the rate and term entered.

Deposit

The cash you contribute up front, also called a down payment. It adds to the price you can reach and reduces the loan you need.

Loan to value

The loan as a percentage of the property value. It governs the rates offered and whether mortgage insurance is required.

Mortgage insurance

A premium many lenders require when the deposit is small. It adds to the monthly cost and therefore reduces borrowing power.

Buying costs

One-off fees to complete a purchase, such as legal work, valuation, searches, and purchase taxes. They come from the same savings as the deposit.

Purchase tax

A government levy on property transactions, known by different names in different countries. It is often the largest single buying cost.

Valuation

A lender’s assessment of what the property is worth. If it comes in below the agreed price, the shortfall usually falls on the buyer in cash.

Housing ratio

The share of gross income a lender allows for the housing payment alone. It is one of the two ceilings behind the loan figure.

Total-debt ratio

The share of gross income allowed for all monthly debt payments including housing. The lower of the two ceilings sets your loan.

Gross income

Income before tax and deductions. Lenders assess against it, which is why an affordable-looking price can still feel demanding.

Escrow costs

Property tax and insurance collected inside the monthly payment. They reduce the amount available for principal and interest.

Association charges

Recurring dues for a managed building or development. Lenders count them within the housing payment.

Principal and interest

The part of the payment that services the loan itself, as distinct from taxes and insurance collected alongside it.

Term

How long the loan runs. A longer term lowers the payment and raises the price you can reach without making the property cheaper.

Pre-approval

A lender’s indication of what it would lend after verifying income, debts, and credit. Stronger than an estimate but still not final.

Equity

The share of the property you own outright. It starts as your deposit and grows through repayment and any rise in value.

Payment shock

The jump between what you pay for housing now and what you would pay after buying. Worth testing before committing to a ceiling.

Underwriting

The lender’s full review of credit, income, employment, and the property before a final decision. Ratios are only one input.

Reserves

Savings remaining after the deposit and buying costs. Some lenders require them, and every household benefits from them.

Common mistakes, and what this page will not do

• Counting all your savings as deposit. Legal fees, surveys, and purchase tax come from the same pot. Set them aside first, then treat what remains as deposit.
• Treating the ceiling as the target. It is the most the ratios allow, not the amount to spend. Buyers who are comfortable years later almost always bought below it.
• Ignoring where the deposit lands as a percentage. Crossing a lender threshold can change your rate and remove mortgage insurance. The last few thousand near a boundary is worth far more than its face value.
• Leaving ownership costs blank. Tax, insurance, and service charges are collected with the payment and directly reduce the price you can reach. A considered estimate beats zero.
• Reusing a rate from weeks ago. Capacity is highly sensitive to the rate. An old quote can move the affordable price by a large margin in either direction.
• Assuming the valuation will match the price. Lenders lend against their valuation, not the agreed price. A shortfall is paid in cash by the buyer.
• Forgetting the costs of owning. Maintenance, repairs, and furnishing arrive after completion and appear in no ratio on this page.
• Stretching the term to reach a price. A longer term lowers the payment and raises the ceiling, but the house does not get cheaper. It costs more in interest.
• Spending the reserves. Arriving with nothing left after completion is how a manageable purchase becomes a fragile one. Some lenders test for reserves directly.

What this calculator leaves out: This calculator does not include buying costs, purchase taxes, or moving expenses in the price, check your credit, verify income, model mortgage insurance, guarantee a valuation, or apply any specific lender or country programme rules. It adds your deposit to a loan estimated from the figures you enter.

Frequently asked questions