Savings Growth Calculator

This calculator projects compound growth by adding the monthly contribution and applying the selected annual interest rate as a monthly rate. The chart shows the estimated balance at each year, so you can see how regular saving and compounding work together.

The rate entered is a steady assumption, not a promise. Cash savings rates can move when the Bank of England changes Bank Rate, and investment returns can rise or fall. Tax is not included, so interest inside an ISA and interest in a taxable savings account may have different real outcomes.

Use the result as a practical planning estimate for starting balance, monthly contribution, interest rate, time horizon, growth chart. The calculator is designed to make the main moving parts visible immediately, so it is most useful when you want to compare scenarios, sense-check a decision, or understand why one input changes the final result.

Before relying on the number, check whether your situation includes anything outside the calculator scope. Common examples are local rules, provider fees, payroll timing, special reliefs, bank holidays, tariff changes, exchange-rate markups, unusual tax codes, or personal circumstances that need official guidance or professional advice.

To make the estimate more accurate, use figures from the most recent bill, payslip, lender quote, receipt, official notice or provider screen you have. Rounded inputs are fine for quick comparisons, but precise inputs are better when you are deciding whether something is affordable or comparing two similar options.

Re-run the calculator whenever a key assumption changes, such as a new rate, different term, changed salary, updated threshold, extra fee, altered usage pattern or different date range. Keeping those assumptions fresh is often more useful than trying to make one calculation perfect.

If you are using the result for a formal decision, keep a note of the inputs you used and the date of the calculation. That makes it easier to compare the estimate with a later quote, bill, payslip or official calculation.