What can you expect to pay for a professional polygraph test?

According to Cost Helper, the average cost of a professional polygraph test is between $200 and $800 for a two-hour session. Longer sessions can cost up to $2,000. Some polygraph services offer discounts to those who order multiple tests at the same time.

Polygraph tests usually take a minimum of two hours to complete, though more thorough tests can last as long as six to eight hours. In order to ensure accuracy, polygraph tests must be administered by a certified professional in a controlled environment. The American Polygraph Association states that polygraph tests, when conducted correctly, are between 80 and 98 percent accurate.