When Can I Start My Typing Speed?

You'll need someone or some timing device that can give you a start and stop without interruption. Just open any book up on any page to use as what you'll type from. Typing test are usually performed for 3 minutes, and 3 times in a row. For each test a different set of text should be used.
  Then you simply add up each individual test number of correctly typed words and divide by 3. This is the average number of words per minute that you typed for that test.  Then add all three test average totals and divide by the 3 for the number of tests you performed. The will be your best average and more realistic number of words per minute that you are able to type. Have fun.