The Allowance Question Comes First

Before choosing where to put money, it's worth checking whether tax on the interest is even a real concern for you — the Personal Savings Allowance means many people never pay a penny of tax on standard savings interest at all. The Savings Interest Calculator applies your allowance precisely rather than assuming every saver is in the same position, since a basic-rate and higher-rate taxpayer have meaningfully different allowances.

Premium Bonds work on a prize draw rather than guaranteed interest, which makes them genuinely different to compare against a standard savings account — the Premium Bonds Calculator uses the current prize fund rate to show what a typical, average outcome looks like, while being upfront that any individual month's result is down to chance rather than a fixed return.

An emergency fund and a long-term investment pot serve different purposes and usually shouldn't be judged by the same growth expectations — the Emergency Fund Calculator focuses on how many months of expenses you'd be covered for, while the Investment Calculator is built around long-run compounding instead.