UK Savings Goal Calculator
Find out how long it will take to reach your savings target — whether that is a house deposit, emergency fund, or any financial goal — with compound interest included.
How much deposit do you need for a house in the UK?
The minimum deposit accepted by most mortgage lenders is 5% of the property price, giving a loan-to-value (LTV) of 95%. However, with only a 5% deposit you will have access to a limited number of products, typically at higher interest rates. A 10% deposit (90% LTV) opens up a meaningfully wider range of mortgage products. Saving to 20–25% gives access to the most competitive rates and significantly reduces monthly repayments and total interest paid over the term.
For context on a £300,000 property: a 5% deposit requires £15,000, a 10% deposit requires £30,000, and a 20% deposit requires £60,000. On top of your deposit you also need to budget for stamp duty (use our stamp duty calculator), legal fees (typically £1,500–£3,000), survey costs, and moving expenses. Allow an additional £4,000–£8,000 for purchase costs above and beyond the deposit itself.
The 50/30/20 budgeting rule
A popular budgeting framework suggests allocating 50% of your net income to essential needs (rent, food, transport, utilities), 30% to discretionary spending (eating out, hobbies, subscriptions), and 20% to savings. For aggressive house deposit saving, many people stretch the savings allocation to 25–30% of net pay by cutting discretionary spending. Our calculator shows your monthly savings as a percentage of take-home pay so you can judge how sustainable your plan is. Use our take-home pay calculator if you need to confirm your net monthly figure first.
ISA allowance and tax-free savings
Each tax year you can save up to £20,000 within an Individual Savings Account (ISA), sheltered from income tax and capital gains tax. For first-time buyers, the Lifetime ISA (LISA) is particularly valuable: you can contribute up to £4,000 per year and receive a 25% government bonus — up to £1,000 free money each tax year — when the funds are used to purchase your first home (property value up to £450,000). A LISA can be opened from age 18 up to age 39, and used for a property purchase from age 18. If you are not yet buying, a Cash ISA or easy-access savings account earning competitive interest is also worth considering.
Emergency fund and compound interest
Financial advisers generally recommend holding 3–6 months of living expenses in an easily accessible emergency fund before committing to longer-term goals. This provides a buffer against unexpected events without derailing your savings plan. Once an emergency fund is in place, compounding works powerfully over time — even a 4% annual interest rate meaningfully accelerates a multi-year savings goal. Our calculator models month-by-month compounding so you can see precisely how interest contributes to your total balance alongside your contributions. A pay rise calculator can show how a salary increase could boost your monthly savings capacity if you are planning a career move.
Related calculators
Use the salary calculator to confirm your net pay before setting a savings amount. The take home pay calculator shows your monthly income in detail. Our mortgage affordability calculator helps you plan the property price to aim for. The rent affordability calculator shows how much of your budget renting currently consumes. Our pay rise calculator shows how a salary increase would change your savings capacity. The stamp duty calculator helps you budget for purchase costs on top of your deposit.
Frequently asked questions
The minimum deposit accepted by most lenders is 5% of the property price. However, a 10% deposit (90% LTV) gives access to a much wider range of mortgage products at better rates. A 20% deposit (80% LTV) is considered comfortable and unlocks competitive pricing. In addition to the deposit, you should budget for stamp duty, legal fees, survey costs, and moving expenses — typically an additional £4,000–£8,000 depending on the property value and location.
A Lifetime ISA (LISA) is the most tax-efficient wrapper for first-time buyers — you can contribute up to £4,000 per year and receive a 25% government bonus (up to £1,000/yr). The money grows tax-free and the government bonus is paid on top when used to purchase a first home worth up to £450,000. A Cash ISA or stocks and shares ISA also shelter savings from tax within the annual £20,000 allowance. High-interest easy-access savings accounts are worth comparing outside an ISA wrapper as rates can be competitive.
The 50/30/20 budgeting rule suggests allocating 20% of net income to savings. For aggressive deposit saving, many people target 25–30% of take-home. Our calculator shows your savings as a percentage of take-home pay so you can judge sustainability. If you are not sure of your take-home, use our take-home pay calculator first to get an accurate monthly figure to work from.
The tax-free status of an ISA does not directly affect a mortgage application, but lenders will ask for evidence of your deposit via bank or ISA statements showing the origin and amount of funds. A Lifetime ISA demonstrates disciplined long-term saving, which is viewed positively. The government bonus in a LISA is only released when you complete the purchase of a first home — it cannot be withdrawn as cash without a 25% penalty (which is effectively more than the bonus itself).