Savings growth
Enter how much you have now and how much you’ll save each month to estimate how your balance could grow.
This estimate assumes monthly contributions and a fixed annual interest rate.
Results
These are estimates based on your inputs.
How this calculator works
We apply a fixed monthly interest rate derived from the annual rate and add your monthly contribution. Results are estimates and real returns may vary.
What this calculator does
This savings growth calculator estimates how your balance could grow over time when you add a fixed monthly contribution and earn interest. It helps you see the combined effect of saving regularly and compound growth.
Use it for planning longer-term goals like an emergency fund, a home deposit, or a large purchase where you want to understand the end balance rather than the monthly target.
How the formula works
We convert your annual interest rate into a monthly rate and apply it to your balance each month. Your monthly contribution is added after interest is applied, then repeated for the total number of months.
The calculator also splits the final total into money you contributed and interest earned so you can see how much growth came from interest alone.
Worked example
Example: you start with £2,000, add £200 per month, earn 4% interest, and save for 5 years. That gives 60 months of contributions. The estimate shows a final balance around £16,500, with the rest coming from interest.
If you raise the monthly contribution or extend the time period, the final balance increases significantly because interest compounds on a larger base.
Common mistakes
- Using a promotional rate that only applies for a short period.
- Forgetting to update the contribution amount when your budget changes.
- Mixing up monthly and annual rates.
- Assuming the result is guaranteed rather than an estimate.
When to use this calculator
Use this when you already know how much you can save each month and want to estimate your end balance. If you instead have a target amount and deadline, use the Savings goal calculator to back-calculate the monthly amount.
FAQs
Is this based on monthly or annual compounding?
The calculator assumes monthly compounding because contributions are monthly. If your account compounds annually, results will be slightly different.
Can I include an annual bonus contribution?
This version assumes a fixed monthly amount. For bonuses or irregular payments, use the estimate as a baseline and adjust the monthly contribution upward.
How do I choose the interest rate?
Use the AER of the account you plan to use. If you are unsure, choose a lower rate to reflect a conservative estimate.