Use this mortgage deposit calculator to see how much deposit you need for a home, what loan to value (LTV) that gives you and how long it will take to save. Tick the Lifetime ISA box to add the 25% government bonus.
Your deposit
- Deposit needed
- –
- Mortgage needed
- –
- Still to save
- –
- Time to save
- –
In the example, a 10% deposit on a £250,000 home is £25,000. With £8,000 saved and £500 a month going in, you would reach it in 2 years 10 months.
How to use the mortgage deposit calculator
- Enter the property price you are aiming for.
- Choose your deposit as a percentage, from 5%.
- Enter your savings so far and how much you can save each month.
- Tick Lifetime ISA if you save in one.
How much deposit do you need?
The minimum is usually 5%, but bigger deposits get cheaper rates. Lenders set rates in LTV bands, typically 95%, 90%, 85%, 80%, 75% and 60%. Moving from a 5% to a 10% deposit can cut the rate noticeably.
| Price | 5% | 10% | 15% | 25% |
|---|---|---|---|---|
| £150,000 | £7,500 | £15,000 | £22,500 | £37,500 |
| £200,000 | £10,000 | £20,000 | £30,000 | £50,000 |
| £250,000 | £12,500 | £25,000 | £37,500 | £62,500 |
| £300,000 | £15,000 | £30,000 | £45,000 | £75,000 |
| £400,000 | £20,000 | £40,000 | £60,000 | £100,000 |
Saving faster with a Lifetime ISA
If you are aged 18 to 39, you can open a Lifetime ISA and pay in up to £4,000 a year. The government adds 25%, up to £1,000 a year, and you can use it towards a first home costing £450,000 or less. See GOV.UK Lifetime ISA. The mortgage deposit calculator adds the bonus on up to £333 a month.
Other costs to save for
- Stamp duty, unless you are a first-time buyer under the relief limits.
- Solicitor or conveyancer fees, often £1,200 to £2,000.
- Survey, from about £400 to £1,500.
- Mortgage fees, removals and furniture.
Help with your deposit
Family can give you a gifted deposit, with a letter confirming it is not a loan. A guarantor or family springboard mortgage can also help; see the guarantor mortgage calculator. Shared ownership needs a deposit only on the share you buy; see the shared ownership mortgage calculator.
Mortgage deposit calculator: worked example
Jess wants a £250,000 flat. A 5% deposit is £12,500 and a 10% deposit £25,000. She has £8,000 and saves £500 a month. The mortgage deposit calculator shows she reaches 5% in 9 months and 10% in 2 years 10 months. With a Lifetime ISA, the bonus brings the 10% target forward by several months.
Waiting for the bigger deposit could cut her mortgage rate, but house prices may rise in the meantime, so run both options.
Frequently asked questions
How much deposit do I need for a £200,000 house?
£10,000 for a 5% deposit, £20,000 for 10% and £30,000 for 15%.
Is a 5% deposit enough?
Yes, 95% mortgages are widely available, but rates are higher and you need to pass stricter affordability checks.
Does the mortgage deposit calculator include stamp duty?
No. Stamp duty and fees are on top of the deposit.
Can I use a gift as a deposit?
Yes, most lenders accept gifts from family with a signed gift letter.
About this calculator
This mortgage deposit calculator works out deposits and saving time in whole months. Lifetime ISA rules were checked against GOV.UK on 9 November 2026. Results are estimates.