Interest Calculation Services

Need help with complex or large-scale interest calculations? Let our expert team handle it for you—save time, avoid costly errors, and get accurate results you can trust.

Typical Calculations:

  • Calculation of interest on hundreds or thousands of invoices
    • One or multiple invoices by client and on various dates
    • Partial payments can be included
    • Fixed or variable interest rates
  • Calculation of pre and postjudgment interest on one amount or multiple amounts (often judgments) over time, including regular or irregular payments, at fixed or variable interest rates
  • Calculation of balances owed on mortgages, loans, lines of credit, etc. These can become quite complex and include late, partial or unpaid payments, fees, etc.
  • Calculation of interest on arrears such as alimony, rent, salaries, or overtime wages
  • Cost of credit (APR) calculations

How it works:

  1. Initial analysis of your needs with one of our experts by phone
  2. Data calculation settings are discussed (simple or compound interest, compounding frequency, day count, interest rate(s), time period, etc.)
  3. Service cost sent to you
  4. You send the data to the Margill expert, usually in a spreadsheet with due dates, amounts, and a record identifier (anonymous or not). A non-disclosure agreement may be signed by Margill, but we prefer receiving and returning anonymous data.
  5. Problem data is identified (usually invalid dates) and corrected by the client – data then returned to Margill
  6. Calculation results are sent back in Excel or CSV format. Individual detailed calculations can also be sent in PDF format.
    • We can store your results for a specified time period to extract any additional data you require (special balances, interest for a specific time frame, etc.)
    • Our software can also be temporarily “rented” for a few days or weeks so you can extract other information from the resulting calculated data

All calculations are supervised by Marc Gelinas, Attorney, MBA, who has been deeply involved in the field for the over 30 years. Marc is the author of the White Paper: The Lost Art of Interest Calculation , originally published in Real Estate Law & Industry Report.

Business cases:

Interest on invoices:

Calculate the legal interest (variable rates) for over 1,500 invoices owed by as many seperate companies. Anonymized data (with identifiers) was sent to Margill in a simple spreadsheet containing the dates and amounts. The results were sent the following day with summary results and detailed calculations.

Overtime pay:

The mandate was to calculate the interest due on overtime pay for thousands of workers. An Excel file containing the workers’ unique identifiers, the number of hours owed for each date, the hourly rate, and a final calculation date was provided. The interest due to each worker was sent the following day.

For more information on this service please call or email us.   Contact us