The time to reach a savings goal depends on four things: your target, what you have already, how much you add each month and the interest you earn. For example, saving £300 a month towards £20,000 from a £2,000 start at 4% takes about 4 years and 6 months. Saving about £265 a month would hit the same target in five years.
The four numbers that decide your timeline
Every savings plan comes down to:
- Target: the amount you want to reach.
- Starting balance: what you already have.
- Monthly saving: what you add regularly.
- Interest rate: the return on your savings.
Change any one and the others move. You can solve for time (how long will it take?) or for the monthly amount (how much do I need to save to hit this by a date?).
Example: how long will it take?
Suppose you want £20,000, you start with £2,000, save £300 a month and earn 4% a year. The House of Calculator savings tool shows:
- Time to reach goal: 4 years, 6 months
- Total you pay in: £18,200
- Interest earned: £1,874.66
- Final balance: £20,074.66
Interest contributes only a small part here because the sum is modest and the time short. The bulk of the progress comes from your own deposits. As balances and timescales grow, interest matters more, as explained in Compound interest explained, with examples.
Example: how much do I need to save each month?
Now flip it. You still want £20,000 starting from £2,000 at 4%, but you want to get there in five years. The tool gives:
| Item | Amount |
|---|---|
| Save each month | £265.44 |
| Total you pay in | £17,926.52 |
| Interest earned | £2,073.48 |
Saving about £34.56 less each month than the first example simply means waiting six months longer. Neither choice is better; it depends on your deadline and budget.
What affects your result
- Interest rate. Even one percentage point can change the timeline slightly, but rates change, so check your provider rather than assuming.
- Tax on interest. Savings interest can be taxable in some circumstances. The calculator does not include tax, so check GOV.UK or the provider’s information.
- Inflation. Prices rise over time, so the target may need to be higher in future money.
- Consistency. Missed months push the date back. Setting up a standing order on payday makes saving automatic.
Practical tips for reaching your goal faster
- Set a specific target and date rather than saving vaguely.
- Pay yourself first by moving money out on payday.
- Increase your monthly amount whenever your pay rises.
- Put windfalls such as bonuses or tax refunds into the pot.
- Keep your goal money separate from everyday spending.
If your goal is a house deposit, also check how much a lender might allow you to borrow, covered in How much mortgage can you afford?. When the goal is cheaper borrowing rather than saving, Loans, APR and car finance: comparing the real cost explains how to compare the cost of credit.
Checking whether your goal is realistic
If the monthly figure looks too high, you have three levers: save for longer, aim lower, or start with more. Try each in the calculator and compare. For example, extending a plan by a year reduces the monthly amount, while a lump sum at the start gives interest more time to work. It also helps to keep an emergency fund separate, so an unexpected bill does not force you to dip into the pot and delay the target.
Reviewing your plan every few months keeps it realistic. If your pay, spending or the interest rate changes, enter the new numbers and see whether the date has moved.
Note: This is general information, not financial advice. The tool assumes a constant interest rate added monthly and gives estimates; real savings rates vary.
Try the calculator
Use the Savings goal and interest to find either your time to target or your monthly saving. To see how a lump sum plus monthly deposits could grow over a fixed period, try the Compound interest.
Open the free Savings goal and interest
Frequently asked questions
How do I work out how long it will take to save?
Divide the amount you still need by what you save each month for a basic estimate, then allow for interest, which shortens the time a little. The calculator does the full calculation.
How much should I save each month?
It depends on your target, your deadline and your budget. Work out the target, choose a date and let the tool show the monthly amount.
Does interest make a big difference on short goals?
Not usually. In the example above, interest was £1,874.66 of a £20,074.66 balance. Your own deposits matter most on shorter timescales.
Is the interest taxed?
Sometimes. Whether you pay tax depends on your circumstances and the account, so check GOV.UK or your provider. The tool does not include tax.