Plot No. 30 · Money & Finance
Down Payment Calculator
Work out the cash deposit you need from a property price and a down payment percentage, and see the mortgage left to borrow. The down payment is the price multiplied by your chosen percentage, the loan is the price minus that deposit, and the loan-to-value ratio is the loan divided by the price. Lower LTV usually means better mortgage rates.
Stamp duty, legal and valuation fees are paid on top of the deposit. Keep extra cash aside rather than putting everything into the down payment.
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How the down payment is worked out
The calculator turns a property price and a deposit percentage into three figures. Your down payment is the price multiplied by the percentage. The mortgage you need is the price minus that deposit. Your loan-to-value ratio is the mortgage divided by the price, expressed as a percentage, which is simply 100% minus your deposit percentage.
Loan-to-value matters because it drives the rate lenders offer. A bigger deposit means a lower LTV, which lenders see as less risky and reward with cheaper interest. Crossing below the 90%, 80% or 75% LTV thresholds often moves you into a better rate band, so a slightly larger deposit can pay for itself.
How to use the down payment calculator
- Enter the property price you are aiming for.
- Enter the percentage you plan to put down as a deposit.
- Read the down payment in pounds, the mortgage needed and your LTV, then try a higher percentage to see how the LTV falls.
Worked examples
Standard 15% deposit
Inputs: Property price 250,000, 15% down payment
Result: Down payment 37,500, mortgage needed 212,500, loan-to-value 85.0%.
Pushing to a 25% deposit
Inputs: Same 250,000 home, 25% down payment
Result: Down payment 62,500, mortgage 187,500 and LTV drops to 75.0%, often a better rate band.
Limitations and common mistakes
Edge cases and limitations
- It covers only the deposit and mortgage split. Stamp duty, legal, survey and moving costs are paid on top.
- It does not check whether a lender will actually offer the mortgage, which depends on income and affordability.
- Rate bands differ between lenders, so hitting a round LTV does not guarantee a cheaper deal.
Common mistakes
- Putting every spare pound into the deposit and leaving nothing for stamp duty and fees.
- Aiming just above an LTV threshold (say 81%) when a slightly bigger deposit to reach 80% could cut the rate.
Frequently asked questions
How much down payment do I need for a house?
In the UK a 5% deposit is usually the minimum, 10% to 15% is common, and 20% or more unlocks the best rates. On a £250,000 home, a 15% down payment is £37,500, leaving a £212,500 mortgage at 85% loan-to-value.
What is loan-to-value (LTV)?
LTV is the mortgage as a percentage of the property price, so it is 100% minus your deposit percentage. A bigger deposit means a lower LTV, which lenders see as less risky and tend to reward with cheaper interest rates. Dropping below 90%, 80% or 75% LTV often moves you into a better rate band.
Does the down payment include other buying costs?
No. This calculator only covers the deposit and mortgage split. Budget separately for costs like stamp duty, valuation and legal fees, and moving expenses. Those are paid on top of your deposit, so keep extra cash aside rather than putting every penny into the down payment.
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