Loan to Value Calculator

Loan-to-value is the mortgage balance measured against the property's current value, and it is one of the most widely used ratios in mortgage lending. Lenders commonly band borrowers by LTV and price each band differently: lower bands are usually priced at lower rates, while high-LTV loans often carry a rate premium and, in some markets, a mandatory insurance premium on top. At the sample figures used on this page (a 240,000 balance on a 300,000 property), the ratio is 80.00%, and the calculator also shows how far that sits from the next band down.

Which inputs matter most

The two inputs do not behave the same way. The balance is a linear lever: a 1% change in it moves the ratio by 1% of the ratio itself, which at an 80% ratio is 0.80 percentage points, the same size up or down. Property value is not linear, because it sits in the denominator: from an 80% ratio a 1% higher value moves the ratio 0.79 points down, while a 1% lower value moves it 0.81 points up. The asymmetry widens as the change grows, which is why the What-If cards show a 10% fall in value adding 8.89 points while a 10% rise removes only 7.27. Those sizes are properties of an 80% ratio rather than of any price level or currency, and they hold anywhere the ratio does. A falling market moves LTV against a borrower faster than an equivalent rise moves it back.

What's happening under the hood

The calculation divides the outstanding balance by the current property value and multiplies by 100. The denominator is current market value rather than the original purchase price, because that is what a lender bands against: a property bought years ago at a lower price can sit in a much lower band today without a single extra payment having been made. The ratio is scale-free, so it behaves identically in every currency and at every price level: only the relationship between the two figures matters, not their size. What the tool returns is a point-in-time reading of the two figures entered, not a projection.

Reading the band rows

Below the ratio the calculator names the illustrative band the result falls into, then states the two ways of reaching the next band down: the overpayment that would do it at today's valuation, and the rise in property value that would do it at today's balance. Both rows are scale-free. From an 80% ratio, the overpayment that reaches the 75% band is 5% of the property value and the value rise is 6.67% of it (a third more) at every price level and in every currency. That one-third gap is a property of the boundary rather than of the starting ratio: reaching any boundary takes a value rise larger than the overpayment by a factor of one divided by that boundary, so 1.33 times for a 75% target and 1.67 times for a 60% one. The band boundaries used here are illustrative breakpoints rather than any lender's schedule.

Why this matters

LTV sits at the heart of mortgage pricing and equity position. Where the ratio sits today, and how far it is from the nearest band boundary, is the context in which overpayments and remortgage timing are usually considered, and it sizes how much room the equity cushion gives if property values move. The ratio also describes to a lender how much of the property's value is at risk on a given loan.

What this doesn't capture

LTV is a snapshot calculated from the two figures entered. It does not account for changes in property value between valuations, ongoing repayments that reduce the balance over time, or a second loan secured against the same property; a combined loan-to-value calculation adds that second balance before dividing. The figure is only current as of the balance and valuation entered.

Where to go next

This calculation rarely sits alone. The Mortgage Calculator derives the payment behind the balance, the Home Equity Calculator works the same relationship from the equity side, and the Mortgage Overpayment Calculator shows what regular extra payments do to the balance that drives this ratio.