Probably not a great idea...
This Income and Expenses spreadsheet will put the important information at your fingertips. By helping you to quickly record income and expenses, you'll know how your properties are operating at any point in time.
Additionally, it helps you know your expense ratio, cash flow ratios, and breakdown of expenses so you know exactly what categories you can target to get your costs down.
You can easily visualize your expenses as a ratio of income (Remember the 50% rule?). This way, if your expenses are ticking up as a percentage of your income, you know that your rents are too low or your expenses are too high and you can adjust operations accordingly.
You can also easily print out the output and save it for quick reference.