Property Calculator Guide
Understand the key figures behind buying or investing in property — deposit and loan-to-value, Stamp Duty, mortgage affordability, rental yield, and return on investment.
The Key Figures Behind Buying Property
Whether you are buying a home to live in or investing in a rental property, the same core figures shape whether a purchase makes financial sense. Understanding each one helps you compare properties on a like-for-like basis.
Deposit and Loan-to-Value (LTV)
Your deposit is the portion of the purchase price you pay upfront, with the rest covered by a mortgage. The remaining mortgage amount, expressed as a percentage of the property value, is your Loan-to-Value — a lower LTV usually unlocks better interest rates.
Stamp Duty Land Tax (or equivalent)
Buyers in England and Northern Ireland pay Stamp Duty Land Tax above certain thresholds, with different rates for first-time buyers, additional properties, and non-resident buyers. Scotland and Wales apply their own separate land transaction taxes.
Mortgage Affordability
Lenders assess how much they are willing to lend based on income multiples, existing debts, and outgoings for residential mortgages, while buy-to-let affordability is typically judged mainly on the property’s expected rental income.
Rental Yield and Return on Investment
For investment properties, gross rental yield compares annual rent to purchase price, while net yield accounts for running costs. Return on investment goes further, factoring in the deposit invested and any capital growth over time.
Property Figures Quick Facts
Essential insights for UK property buyers and investors
Key Metrics At A Glance
A quick overview of the core figures used when evaluating a property purchase or investment.
| Metric | What It Measures | Typically Used By | Affected By |
|---|---|---|---|
| Loan-to-Value (LTV) | Mortgage amount as a percentage of property value. | Homebuyers and lenders. | Deposit size, property valuation. |
| Stamp Duty / Land Tax | Tax due on completion of a property purchase. | All buyers above relevant thresholds. | Purchase price, buyer status, number of properties owned. |
| Affordability Multiple | Maximum mortgage relative to income. | Residential mortgage applicants. | Income, debts, credit history, outgoings. |
| Gross Rental Yield | Annual rent as a percentage of purchase price. | Buy-to-let investors. | Rent achievable, purchase price. |
| Net Rental Yield | Annual rent minus running costs, as a percentage of purchase price. | Buy-to-let investors. | Maintenance, fees, insurance, mortgage interest. |
Property Calculator FAQ
Answers to the most frequently asked questions about buying and investing in UK property.
Loan-to-Value is the size of your mortgage expressed as a percentage of the property’s value. A lower LTV, meaning a bigger deposit relative to the purchase price, generally gives access to better mortgage interest rates.
Not always. Stamp Duty Land Tax in England and Northern Ireland is only payable above certain price thresholds, and first-time buyers often benefit from relief up to a higher threshold than other buyers. Scotland and Wales have their own separate land transaction taxes with different rates.
There is no single ‘good’ figure, as it depends on the area and property type, but many investors look for a gross rental yield in the region of 5% to 8% as a reasonable benchmark, while accepting that yields vary significantly by location.
Lenders typically assess affordability based on a multiple of your income, alongside your existing debts, regular outgoings, and credit history, rather than income alone. Buy-to-let affordability is usually assessed differently, based mainly on expected rental income.
Gross yield is calculated using annual rental income as a percentage of the property’s purchase price, without deducting costs. Net yield subtracts running costs, such as maintenance, letting agent fees, insurance, and mortgage interest, giving a more realistic picture of actual return.