Most people will live long enough to retire from their jobs and live on retirement money. The most common account used for retirement money is a 401(k) account. An employer will withhold a certain percentage of money from an employee’s paycheck and put it into the 401(k) account. A person can use a simple 401k calculator to figure out how much he or she will have by the time he or she retires. As a matter of fact, it has been calculated that a person can have as much as a million dollars or more by the time he or she retires.