According to govt rule, when and what base a company paid bonus to a employee.It is on company performance
Please give me little basic idea on bonus calculation

First its not a good idea to piggyback your question on another thread. This can lead to confusion. So I've moved your question to its own thread.

There is no government rule. A company can base their bonus on anything they want. It could be on whether the average temperature reaches a certain threshold if they want. As long as the bonus calc is applied fairly and equitably, that's all the government cares about.

The question is a bit misleading. I think what you may be asking is "What is the correct way to calculate the bonus for tax purposes?"

You are allowed to use the supplemental tax rates for federal and state

Or

You are allowed to use the aggregate method. In this method you would add the amount to the last payroll, then figure out the difference in the taxes between the last payroll and the last payroll with the bonus amount added. You than pay the difference for the bonus.

These are the only two methods allowed by the IRS. You can find complete instructions in the Circular E tax booklet on Internal Revenue Service look for publication 15. It will be on page 13 of the booklet.

Shirley