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Total Interest Calculator UK

Calculate total interest earned on savings over time, including compound growth, monthly contributions and projected final balances. Ideal for comparing savings plans and seeing how your money can grow.

Build your account mix

Track the total effect of multiple savings, investment and debt accounts without changing the underlying projection logic.

Add as many asset and debt accounts as you want. Use monthly contributions for savings or investing and monthly overpayments for debts. Optional caps let you limit further contributions or the balance that continues to earn interest.

Total Interest Calculator UK

This total interest calculator UK helps you estimate how much interest you can earn on your savings over time. Whether you are starting with a lump sum, adding monthly deposits, or comparing different savings plans, it shows how compound interest can increase your final balance.

It is useful for UK savers who want to plan towards a target, compare account options, or understand how much of their future balance comes from contributions versus interest earned.

What this calculator includes

  • Starting balance or initial deposit
  • Monthly contributions or regular savings
  • Annual interest rate or expected return
  • Savings period in years and months
  • Compound interest growth over time
  • Total interest earned and projected final balance
  • Multi-account support for broader comparison planning

How it works

The calculator applies interest to your balance over the selected period and adds the effect of compounding, so you earn interest not only on your original savings but also on interest already added. If you enter monthly contributions, each new deposit is added into the projection and starts earning interest from that point onward.

For broader planning, you can also compare multiple balances in one place to see your overall projected growth, but the core purpose is to show how savings interest builds over time.

Example calculation

If you start with £10,000, earn 5% annual interest and leave it invested for 5 years, your estimated results would be roughly:

  • Total interest earned: about £2,760
  • Final balance: about £12,760

If you also add monthly savings, your total interest can rise much faster because each contribution has more time to compound.

Why results vary

  • Real savings accounts may compound daily, monthly or annually
  • Interest rates can change, especially on variable-rate accounts
  • Introductory bonus rates may not last for the full term
  • Taxes, fees or account restrictions can affect your actual return
  • Some providers cap how much balance earns the full advertised rate

Who it’s for

  • UK savers planning short-term or long-term goals
  • People comparing savings accounts or cash ISA options
  • Anyone building an emergency fund
  • Users wanting to understand compound interest in plain English
  • Savers checking how regular monthly deposits affect total growth

Important note

This calculator provides estimates only and does not constitute financial, tax, savings or investment advice. Actual results may differ depending on account terms, compounding frequency, rate changes, fees and your personal tax position. Always check the provider’s terms before making financial decisions.

Use the calculator above to estimate your total interest, compare different savings scenarios and see how your balance could grow over time.

Total Interest Calculator UK – FAQs

Savings interest is usually calculated using compound interest. That means you earn interest on your original balance and on previously added interest, which increases growth over time.

AER stands for Annual Equivalent Rate. It shows the effective yearly rate after compounding, making it easier to compare UK savings accounts fairly.

Your real results may differ because banks can use different compounding frequencies, variable rates, account limits, bonus periods or other product-specific rules.

You may need to pay tax if your savings interest exceeds your Personal Savings Allowance. The amount depends on your income tax band and whether the money is held in a tax-free wrapper such as an ISA.

Yes. Regular contributions can significantly increase your final balance and total interest earned, especially over longer periods because each deposit has time to compound.

Yes. Try different interest rates, contribution levels and time periods to compare how different accounts may affect your total interest and projected balance.

No. This page can also support multiple balances, which is useful if you want a wider view of your savings and interest position. For simple scenarios, you can use it like a standard total interest calculator with a single account.

You can usually improve your total interest by choosing a higher AER, saving regularly, keeping money invested for longer and reviewing rates when introductory offers end.