Use Personal Financial SoftwarePrograms such as Microsoft Money and Intuit's Quicken can help keep track of investment transactions. Many brokerage firms will even let you download your data directly into these programs. The best thing about downloading your brokerage data is that you can keep track of every single transaction, such as dividends paid and reinvested.
Use Cost Basis Tracking from Your BrokerMany of the larger brokerage firms will track your cost basis for you. This is an extra service, and you have to request it. Several brokers provide cost-basis tracking at no additional charge. How it works: the broker will keep track of the price you paid for each stock, mutual fund, or other investment you make. When you go to sell the investment, the broker will match up your cost basis with your selling price and report your capital gains to you.
Cost basis tracking will work best for you only if you use the same broker to buy and to sell your investments. Otherwise, your cost basis information may get lost when switching brokers.
Use a Spreadsheet ProgramYou can use a spreadsheet program, such as Microsoft Excel or OpenOffice's Calc to keep track of your investments. This requires a bit more work to set up than using Quicken, but you can customize your spreadsheet to suit your needs. The key to setting up a capital gains spreadsheet is to enter your investment transactions regularly and consistently. Here's an example of a columns and rows for setting up a very basic capital gains spreadsheet.
|Capital Gains Worksheet|
|A.||Description of Security||100 shares XYZ|
|H.||Cost Basis||= C + D + G||1250|
|I.||Capital Gain||= F - H||102|
|J.||Short-Term or Long Term||LT|