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To use the simple interest calculator you will need to input your 'interest rate (per annum)' manually.  So, for example, if you are applying the current judgment rate of interest to a judgment debt, you will have to check in advance what this rate is according to the legislation in force at the date of judgment or the statutory implied rate under the Late Payment of Commercial Debts (interest) Act.

For more complex debts with variable rates over time or compound interest, you can still use the simple interest calculator, but you will need to input and print out separate calculations following any date when the rate changes or interest compounds, adjusting the next period's interest rate (per annum)' or principal sum accordingly.

Click on the link to access our simple interest calculator.

Should you have any questions concerning the operation of the simple interest calculator Theo Anderton, partner in our Restructuring and Insolvency group in London on 020 7814 6916 or by email at