Calculate your deposit amount, mortgage loan amount, loan-to-value (LTV), and monthly mortgage payment.
Rates as of Q2 2025 (example)
A deposit calculator works out how much deposit you'd need for a property purchase based on a percentage of the property price, along with the resulting mortgage loan amount, loan-to-value (LTV) ratio, and an estimated monthly mortgage payment. This is useful for first-time buyers and movers working out how much they need to save, and for understanding how the size of a deposit affects the mortgage required.
The deposit amount is simply a percentage of the property price, and the loan amount (the mortgage you'd need) is the remainder. The LTV ratio expresses the loan amount as a percentage of the property price — a lower LTV means a larger deposit relative to the property value.
Formula: Deposit Amount = Property Price × (Deposit % ÷ 100). Loan Amount = Property Price − Deposit Amount. LTV % = (Loan Amount ÷ Property Price) × 100. Monthly Payment = [Loan Amount × r × (1+r)n] / [(1+r)n − 1], where r is the monthly interest rate and n is the number of months.
Example: For a £300,000 property with a 10% deposit, the deposit amount is £30,000, and the loan amount is £270,000 — a 90% LTV. At a 5.25% interest rate (example rate — enter your actual rate) over 25 years, the estimated monthly payment is roughly £1,618. (Note: all figures in this example are for illustration purposes only and do not represent a mortgage offer.)
The size of your deposit directly affects your loan-to-value (LTV) ratio, which is one of the most important factors in the mortgage rate you're offered — lenders typically offer better rates at lower LTV bands (such as 60%, 75%, 85%, 90%, or 95%), so even a small increase in deposit that moves you into a lower LTV band can meaningfully reduce your interest rate. Most mainstream lenders require a minimum deposit of around 5-10% of the property price, with 95% LTV mortgages available from some lenders (sometimes via government-backed schemes). First-time buyers may also be eligible for schemes such as a Lifetime ISA (LISA), which offers a government bonus on savings used toward a first home, helping to build a deposit faster (see the Lifetime ISA Calculator). Remember that buying a property also involves other upfront costs — such as Stamp Duty Land Tax, solicitor fees, and survey costs — which are separate from your deposit and should be budgeted for in addition.
Loan-to-value (LTV) is your mortgage loan amount expressed as a percentage of the property price. A 90% LTV means you're borrowing 90% of the property value and providing a 10% deposit. Lower LTVs generally qualify for better mortgage rates.
Most mainstream lenders require a minimum deposit of around 5-10% of the property price, though some lenders offer 95% LTV mortgages (borrowing 95% with a 5% deposit), sometimes through government-backed schemes. Larger deposits generally unlock better interest rates.
No. This calculator focuses on the deposit, loan amount, and resulting mortgage payment based on the property price. Stamp Duty Land Tax, solicitor fees, surveys, and moving costs are separate upfront costs that should be budgeted for in addition to your deposit — use the Stamp Duty Calculator for that estimate.
Lenders typically offer better interest rates at lower LTV bands (e.g., 60%, 75%, 85%, 90%, 95%). Increasing your deposit — even by a relatively small amount — can sometimes move you into a lower LTV band, unlocking a meaningfully better rate on the whole loan amount.
Yes, for eligible first-time buyers. A Lifetime ISA (LISA) allows you to save toward a first home (or retirement) with a government bonus added to your contributions, up to certain limits. See the Lifetime ISA Calculator to estimate how this could boost your deposit savings.
No — the default is an example only. Mortgage rates vary by LTV band, lender, and product type, with lower LTVs (larger deposits) generally accessing better rates. Enter the actual rate offered for your specific LTV band for an accurate monthly payment estimate.
Disclaimer: The information, rates, and figures provided on this page are for educational and illustrative purposes only and do not constitute a mortgage offer or financial advice. The default interest rate is a sample value and does not reflect rates currently available from any specific lender or LTV band. Mortgage rates, deposit requirements, and lending criteria vary by lender and change frequently. Always obtain a personalised quote from a mortgage lender or broker and consult a qualified financial adviser before making any property purchase decisions.