This Mortgage Deposit Calculator helps you calculate how long you will need to save for to reach the required deposit to purchase a home in the UK. Whether you’re a first-time buyer or moving up the property ladder, understanding your deposit is the first step to homeownership.
What is a Mortgage Deposit and Why Does it Matter?
A mortgage deposit is the upfront cash you put towards the purchase of a property. In the UK, most lenders require a minimum deposit—usually at least 5% of the property price. The bigger your deposit, the less you need to borrow, and the better the mortgage deals you can access. A larger deposit also reduces your loan-to-value (LTV) ratio, which is a key factor in determining your interest rate and monthly payments.
How Much Deposit Do You Need? (Table)
The table below shows the minimum deposit required for different property prices and LTVs:
| Property Price | 5% Deposit | 10% Deposit | 15% Deposit | 20% Deposit |
|---|---|---|---|---|
| £150,000 | £7,500 | £15,000 | £22,500 | £30,000 |
| £200,000 | £10,000 | £20,000 | £30,000 | £40,000 |
| £250,000 | £12,500 | £25,000 | £37,500 | £50,000 |
| £300,000 | £15,000 | £30,000 | £45,000 | £60,000 |
| £400,000 | £20,000 | £40,000 | £60,000 | £80,000 |
Note: Most lenders require at least a 5% deposit, but a 10% or larger deposit will unlock better rates and more options.
How your deposit impacts home affordability
Your deposit size directly affects your loan-to-value ratio, which is the percentage of the property price you borrow. A lower LTV means less risk for the lender, so you’ll usually get lower interest rates and cheaper monthly payments. For example, a 10% deposit (90% LTV) will get you a better deal than a 5% deposit (95% LTV). A larger deposit also means you borrow less overall, reducing your total interest paid.
Example: Saving for a Deposit
Let’s say you want to buy a £250,000 home with a 10% deposit (£25,000). You currently have £5,000 saved and can put away £500 per month. Here’s how you could reach your goal:
- Starting savings: £5,000
- Monthly savings: £500
- Target deposit: £25,000
- Amount left to save: £20,000
- Time needed: £20,000 ÷ £500 = 40 months (about 3 years and 4 months)
If you can increase your monthly savings or get a bonus (e.g., from a Lifetime ISA), you could reach your goal faster.
Tips for Saving a Deposit Faster
Saving for a deposit can be challenging, but there are ways to speed up the process. Here are some practical tips:
- Open a Lifetime ISA (LISA) for a 25% government bonus on your savings (up to £1,000/year)
- Set up a dedicated savings account to keep your deposit separate
- Automate monthly transfers to build your deposit consistently
- Cut back on non-essential spending and redirect the savings
- Consider government schemes like Help to Buy or Shared Ownership
- Ask family for help with a gifted deposit (if possible)
Every little bit helps—review your budget regularly and look for ways to boost your savings.
How this deposit calculator works
This calculator takes the expected property value of the home you are looking to purchase and calculates the size of the deposit needed based on a percentage. You will then enter the current savings that you have in addition to regular contributions you are able to make. A specific length of time can be entered if you want to know how much money you will have by a certain date. This will help calculate either how long it will take to save the required amount as well as the likely amount you will have saved.
Frequently Asked Questions
Can I get a mortgage with a 5% deposit? Yes, but your choice of lenders and rates will be more limited. A bigger deposit gives you more options and better deals.
What is a gifted deposit? A gifted deposit is money given to you (usually by family) to help with your home purchase. Lenders will want proof it’s a gift, not a loan.
Do I need to show where my deposit came from? Yes, lenders require evidence of your deposit’s source to comply with anti-money laundering rules.
Can I use a Lifetime ISA for my deposit? Yes, if you’re a first-time buyer and meet the scheme’s criteria.
Does a bigger deposit always mean a better rate? Generally, yes. The bigger your deposit, the lower your LTV, and the better the rates you’ll be offered.
What other costs should I budget for? Besides your deposit, you’ll need to cover Stamp Duty, legal fees, surveys, and moving costs.
How your deposit impacts home affordability
The deposit that you have saved for a home puchase in the UK can help you access lower rates which will help make mortgage payments more affordable. This is a result of the deposit size having a direct relationship with the loan-to-value ratio. Having a larger deposit also means that you will need to take out a smaller loan which will reduce the total amount borrowerd. This will also have an impact on the affordability of mortgage payments.
How this deposit calculator works
This calculator takes the expected property value of the home you are looking to purchase and calculates the size of the deposit needed based on a percentage. You will then enter the current savings that you have in addition to regular contributions you are able to make. A specific length of time can be entered if you want to know how much money you will have by a certain date. This will help calculate either how long it will take to save the required amount as well as the likely amount you will have saved.
Disclaimer: This calculator uses general assumptions that may differ from your actual results. It is important to seek professional advice from a lender to see how much home you can afford.