Book excerpt: The immense power of compound interest is such that adding a small amount of extra principal to each of your mortgage payments will result in thousands (or tens of thousands) in interest savings over the life of your loan. Using only high-school mathematics, Tim Hill provides clear and readable lessons that you can use to understand and pay down your mortgage by using Microsoft Excel (or any spreadsheet software). This entirely practical guide teaches you how to use worksheet functions, array formulas, data tables, and other spreadsheet features to manage your business and personal finances. You'll also learn the auxiliary skills needed to create and maintain financial spreadsheets: rounding numbers, data and time arithmetic, summing and counting values, and more. Plenty of examples show you how to use these tools for any type of debt or savings: mortgages, student loans, leases, credit-card debt, car payments, medical expenses, annuities, and retirement funds. You can download the sample workbooks to follow along with the author's examples and calculations. - Covers all versions of Excel. - Learn about basic financial concepts, including cash flows, timing issues, and the time value of money. - Compute the payments needed to pay off a loan or to meet an investment target. - Separate the interest and principal portions of your mortgage or loan payments for tax purposes. - Convert between the commonly used methods of quoting interest rates. - Create amortization schedules to see how your debts change over time. - Build summary tables to compare loans that have different interest rates, loan amounts, or payment terms. - Derive the true interest rate of your investments or loans, including "interest-free" loans. - See how much time it will take to pay off a loan, meet an investment target, or retire. - Determine how much to invest now to meet a future goal. - Calculate how money will accumulate in your retirement or savings accounts. Contents Part I - Loans & Mortgages 1. Getting Started with Loans & Mortgages 2. Present Value (PV) 3. Future Value (FV) 4. Payments (PMT) 5. Interest Rates (RATE) 6. Periods (NPER) 7. Interest and Principal Components 8. Converting Interest Rates 9. Loan Amortization Schedules 10. Summarizing Loan Options Part II - Dates & Times 11. Getting Started with Dates & Times 12. Date & Time Basics 13. Date & Time Functions 14. Date Tricks 15. Time Tricks Part III - Sums & Counts 16. Getting Started with Sums & Counts 17. Counting Basics 18. Counting Tricks 19. Frequency Distributions 20. Summing Basics 21. Summing Tricks