LTV Calculator — Find Your Cheapest Rate Band

Loan-to-value (LTV) is your mortgage balance expressed as a percentage of your property's value. Borrow £200,000 against a £250,000 property, and your LTV is 80% — meaning the remaining 20%, or £50,000, is your equity in the home. Running these numbers through a proper LTV calculator takes the guesswork out of a figure that genuinely drives the price of your mortgage more than almost anything else you control.

It's easy to think of LTV as a background detail that a lender checks once and files away. In practice, it's one of the single biggest levers on what your mortgage actually costs, month after month, for as long as the deal runs. A genuinely useful LTV calculator makes this concrete rather than abstract: it turns "I have some equity" into an exact percentage, and shows precisely which pricing tier that percentage lands you in.

This matters at two distinct moments. When you're buying, your deposit size directly sets your starting LTV, and even a modestly larger deposit can shift you into a noticeably cheaper band from day one. When you're remortgaging, your LTV has usually improved since you first bought, purely from years of repayments and, often, property value growth — but unless you actually check the number, that improvement can go entirely unclaimed, and you end up accepting a rate priced for the LTV you started with rather than the one you're actually at now.

UK lenders don't price mortgages on a smooth curve — they group products into discrete bands, usually at 60%, 75%, 80%, 85%, 90% and 95% LTV. Each band is priced as its own risk tier, so even a fractional move from 81% to exactly 80% can shift you into a meaningfully cheaper product range.

On a typical 5-year fixed rate through 2026, the gap between the best and worst bands is genuinely significant: roughly 3.89% at 60% LTV versus roughly 4.75% at 85% LTV. On a £200,000 balance over 25 years, that difference works out to around £100 a month, or roughly £6,000 over a 5-year fixed term.

Save a bigger deposit before a purchase — the most direct lever available. Make mortgage overpayments ahead of a remortgage, specifically timed to cross a band boundary rather than simply reducing the balance generally. Let time and property growth work for you — your LTV naturally improves as you repay capital and, in a rising market, as the property's value increases, though this second factor is never guaranteed. Add genuine value through home improvements can also help, though a formal valuation is needed to confirm any uplift actually counts.

Buy-to-let mortgages typically cap at a lower maximum LTV than residential lending — usually 75% to 80%, compared with up to 95% for standard residential purchases. Lenders also layer on additional affordability tests specific to buy-to-let, most notably the Interest Cover Ratio (ICR), meaning your LTV figure here is a genuine starting point rather than the full picture.

It's genuinely worth revisiting an LTV calculator at three specific points, not just once when you first take out a mortgage. First, roughly six months before your current deal ends, since most lenders let you lock in a new rate ahead of the switch date, and knowing your updated LTV lets you shop with the right figure in mind rather than an outdated one. Second, after any significant overpayment, particularly if it's large enough to plausibly cross a band boundary. Third, if you have reason to believe your property's value has moved meaningfully since your last valuation — a kitchen extension, a loft conversion, or simply a strong local market can shift the number more than people expect.

Checking little and often costs nothing and takes a couple of minutes with a calculator like this one. Skipping the check costs real money, since lenders have no obligation to proactively re-price you into a cheaper band just because your position has quietly improved — that's a step you have to take yourself.

Here's the same maths worked through a real LTV calculator scenario. A property worth £300,000 with a mortgage balance of £231,000. LTV: £231,000 ÷ £300,000 × 100 = 77% — just inside the 75-80% band, but only just. Overpaying £6,000 would take the balance to £225,000, an LTV of exactly 75% — crossing into the noticeably cheaper band and potentially saving hundreds of pounds a year on a future remortgage.

Official sources & further reading: read general mortgage guidance at MoneyHelper, and verify any lender or broker on the FCA register. Model your full remortgage decision with our remortgage calculator, or browse every tool on the mortgage calculators homepage.