Interest Calculator

£0.00
Final Amount
£0.00
Principal
£0.00
Interest Earned
0.00%
Effective Annual Rate

How Interest Works

Interest is the cost of borrowing money or the reward for saving it. When you save money, the bank pays you interest as compensation for letting them use your funds. When you borrow money, you pay interest as the cost of accessing funds you don’t currently have.

Simple vs Compound Interest

Feature Simple Interest Compound Interest
Calculation Base Principal amount only Principal + accumulated interest
Growth Pattern Linear growth Exponential growth
Returns Over Time Consistent annual amount Increasing annual amount
Common Applications Short-term loans, bonds Savings accounts, investments

Compounding Frequency Impact

The frequency of compounding significantly affects your returns. More frequent compounding generally leads to higher returns because interest is calculated and added to the principal more often, creating a compounding effect.

  • Annual Compounding: Interest calculated once per year
  • Quarterly Compounding: Interest calculated four times per year
  • Monthly Compounding: Interest calculated twelve times per year
  • Daily Compounding: Interest calculated every day

UK Interest Rate Environment

Interest rates in the UK are influenced by the Bank of England’s base rate, inflation, and economic conditions. Current typical rates include:

Savings Products

  • Easy Access Savings: 0.5% – 4.5% AER
  • Fixed Rate Bonds: 3.0% – 5.5% AER
  • ISAs: Similar rates to standard savings, tax-free
  • Premium Bonds: Variable, average 1.0% AER

Borrowing Products

  • Personal Loans: 3% – 25% APR
  • Credit Cards: 18% – 35% APR
  • Mortgages: 4% – 7% APR
  • Overdrafts: 19% – 40% EAR

Frequently Asked Questions

AER (Annual Equivalent Rate) is used for savings products and shows what the interest rate would be if paid and compounded annually. APR (Annual Percentage Rate) is used for borrowing and includes the interest rate plus additional charges like arrangement fees.

Inflation reduces the purchasing power of your money over time. If your savings interest rate is lower than the inflation rate, you’re effectively losing money in real terms. It’s important to seek savings rates that at least match or exceed inflation.

UK residents receive a Personal Savings Allowance: £1,000 for basic rate taxpayers, £500 for higher rate taxpayers, and £0 for additional rate taxpayers. Interest above these thresholds is taxed at your marginal rate. ISAs provide tax-free savings up to annual limits.

It’s wise to review your savings rates every 6-12 months, as banks frequently change their offerings. Many savings accounts have introductory bonus rates that decrease after a period, so regular reviews can help maximise your returns.

The Financial Services Compensation Scheme (FSCS) protects deposits up to £85,000 per person, per authorised institution. If you have more than this amount, consider spreading it across multiple banks to maintain full protection.

References

  1. Bank of England. (2024). “Bank Rate and Interest Rates.” Available at: https://www.bankofengland.co.uk/monetary-policy/the-interest-rate-bank-rate
  2. Financial Conduct Authority. (2024). “Savings Products and Interest Rates.” FCA Handbook. London: FCA Publications.
  3. HM Revenue & Customs. (2024). “Personal Savings Allowance: Tax on Savings Interest.” HMRC Internal Manual. London: HMRC.
  4. Financial Services Compensation Scheme. (2024). “Deposit Protection Limits and Coverage.” FSCS Protection Guide. London: FSCS.
  5. Money and Pensions Service. (2024). “Savings and Investments: A Guide for Consumers.” MaPS Financial Guidance. London: MaPS.
  6. Office for National Statistics. (2024). “Consumer Price Inflation: Historical Data.” ONS Statistical Bulletin. London: ONS.