Here's a simple Excel spreadsheet I just put together to give you an idea of what's possible. It opens up in Open Office as well.

These financial formulas are very sensitive to correct positive/negative numbers. For leases, you have to pay attention to the fact that lease payments are calculated at the start of the period. Agricultural loans and leases aren't always monthly, so you need to do a bit more calculation for the number of periods, and the interest rate per period. Follow the example through, and I think you'll get what I mean.

I'm attaching a screen shot, plus the workbook.

(Interest Calculator.JPG)

Interest Calculator.xls (18KB - 120 downloads)

Interest Calculator.JPG (67KB - 85 downloads)