Savings calculator
See how your savings could grow with interest and regular deposits.
Illustrate how a starting balance and regular monthly deposits could grow at a constant savings rate. The result shows total money paid in separately from interest.
Example calculation
Based on the example figures in the form. Enter your own details, then select Calculate.
Illustrative future balance
£44,141.63
- Starting amount
- £10,000.00
- Total paid in, including starting amount
- £34,000.00
- Interest earned
- £10,141.63
An estimate based on the assumptions below. For information only, not financial advice.
How this is calculated
Assumes a constant effective annual rate and contributions at the end of each month. Figures are before tax, fees and inflation. Actual interest depends on the account and its terms.
Calculation method
Future balance = P × (1 + r)ⁿ + C × ((1 + r)ⁿ − 1) ÷ r
P is your starting balance, C is the monthly deposit and n is the number of months. The monthly rate r is (1 + AER ÷ 100)^(1 ÷ 12) − 1. Deposits are added at the end of each month. If the rate is zero, the balance is P + C × n.
Worked example
Start with £1,000 and add £100 each month for two years at 0% interest: the final balance is £3,400. Separately, £10,000 left untouched at a constant 10% effective annual rate for two years becomes £12,100. These are mathematical examples, not available savings offers.
Method documented: · How we check calculations · Report an error
Common questions
What does AER mean in this calculator?
It is the effective annual rate, including the effect of compounding over a year. The calculator converts it to an equivalent monthly rate rather than simply dividing it by twelve.
Does the result include tax on savings interest?
No. It illustrates gross growth before any applicable tax, fees or inflation. Your actual net interest depends on the account and your circumstances.
What if my savings rate changes?
This version uses one constant rate. Compare scenarios with different rates, and check account conditions such as introductory bonuses, deposit limits and withdrawal restrictions.