MyFico.com

This site contains 51 free calculators running the gamut from an interest calculator (listed under “Loan Calculators”), to mortgage, auto loan, debt and credit card, savings, personal finance, investment and retirement calculators. Handy when calculating interest to be paid on a debt in connection with a Chapter 13 Plan or determining the current FMV of collateral such as a car, as well as length of plan and interest rate.

NOTE: One thing MYFICO.com does not have is a calculator to determine interest and penalties on a delinquent tax liability. An application to do this calculation is available from TimeValue.com for a reasonable price.