House Deposit Savings Calculator
Saving for a house deposit takes time, and it helps to know how much you need to put aside each month. This calculator shows the monthly amount needed to reach your savings goal by a date you choose. It allows for interest earned on your savings along the way.
Enter your savings goal, any amount you have already saved, the annual interest rate on the account, and the number of years you have to reach the goal. The calculator then shows the amount to save each month and the total you put in yourself. Use it as a planning tool, and check the rate and figures with your lender or bank before you commit.
How to use the house deposit savings calculator
- Enter your savings goal in pounds, for example the deposit amount you are aiming for.
- If you already have some savings for the deposit, enter that amount in the Saved already box. Leave it blank or at zero if you are starting from nothing.
- Enter the annual interest rate as a percentage, as shown on the savings account you plan to use.
- Enter the number of years you have to reach your goal.
- Read the Save each month figure to see how much to put aside every month.
- Check the Total you put in figure to see how much of your own money you will have contributed by the end.
The formula
- What you have now grows to: saved × (1 + r)^n, with r = annual rate ÷ 12 ÷ 100 and n months
- Monthly saving = (goal − that) × r ÷ ((1 + r)^n − 1)
Worked example
The figures below are made up to show the maths. They are not current prices, rates or product figures.
| Savings goal | £20,000.00 |
|---|---|
| Saved already | £2,000.00 |
| Annual interest rate | 4% |
| Years to reach it | 5 years |
- Save each month £264.83
- Total you put in £17,889.84
Tips for an accurate answer
- Use the interest rate from the account you actually plan to open, and check whether it is a fixed or variable rate.
- Remember that the calculator assumes you save the same amount every month, so build in a small margin if your income varies.
- If the monthly figure is more than you can manage, try a longer time period or a smaller goal and run the calculator again.
- Confirm the amount you need for a deposit with your mortgage lender, as requirements can differ.
- Review your plan regularly, especially if the interest rate changes or you add a lump sum.
Questions people ask
Does this calculator show government schemes for saving a house deposit?
No, this calculator only works out monthly savings from your goal, your starting amount, the interest rate and the time period. It does not cover government schemes. Check the official government guidance for any scheme you are considering.
How do I use a house deposit calculator to plan my savings?
Enter your savings goal, the amount you have already saved, the annual interest rate and the number of years you have. The calculator shows how much to save each month and the total you will contribute yourself. Use the result to check whether your plan is realistic.
What does the house deposit savings calculator work out?
It works out how much you need to save each month to reach your savings goal by the date you choose. Interest on your savings is included in the result. The calculator also shows the total amount you will have put in yourself.
Do I need to include money I have already saved?
Yes, if you already have savings for your deposit, enter them in the Saved already box. The calculator then works out the monthly amount needed on top of what you have. If you are starting from nothing, leave this box blank.
Why is the total I put in less than my goal?
The difference comes from the interest your savings earn over the period. The Total you put in figure only counts the money you add yourself, so interest makes up the rest of the goal. This is why the monthly amount is lower than a simple division of the goal would suggest.
Can I rely on this calculator for a mortgage decision?
The calculator is for planning and shows the maths only. It is not financial advice. Check the figures with your lender or bank before making decisions about your mortgage or savings.
Sources
This calculator uses the standard loan and interest formulas above and the numbers you type. It needs no outside figures.
An estimate from the numbers you enter, worked out with the formula shown. It is maths, not financial advice: your lender or bank has the final figures. Page checked 23 Oct 2026. Read the disclaimer