Lock in a fixed rate or keep flexibility with a variable account? Enter your savings, both rates, the term and how you expect variable rates to move to see which option earns you more interest — and by how much.
Interest over your term
A fixed-rate savings bond locks in a guaranteed rate for a set term (often 1–5 years), so you know exactly what you'll earn — but you usually can't touch the money until it matures. A variable easy-access account lets you withdraw any time, but the provider can cut the rate whenever they like, especially after a Bank of England base-rate change. This calculator pits the two against each other over your chosen term.
Interest from ordinary savings counts toward your Personal Savings Allowance (£1,000 for basic-rate, £500 for higher-rate, £0 for additional-rate taxpayers) — above that it's taxed. A cash ISA shelters interest from tax entirely. Also weigh access: a fixed bond ties up your money, so keep an emergency buffer in easy-access first. Compare specific deals with the fixed rate bond calculator and project growth with the compound interest calculator.
It depends on rate moves and access needs. A fixed bond guarantees today's rate but locks money away; a variable account stays flexible but the rate can be cut. Expect rates to fall? Fixing usually wins. Expect rises? Variable keeps you flexible.
It compounds your savings at the fixed rate for the full term, and compounds the variable account year by year while adjusting its rate by the expected yearly change you enter — then shows which earns more, and by how much.
Possibly — interest counts toward your Personal Savings Allowance (£1,000 basic-rate, £500 higher-rate, £0 additional-rate). Above that it's taxed at your normal rate. A cash ISA shelters interest entirely.
A fixed bond usually blocks withdrawals until maturity (or charges a penalty), so only fix money you won't need. Keep an easy-access buffer. Many savers split — some fixed for rate, some easy-access for flexibility.
