More information would be needed to answer your question.
In general, if income taxes have not been paid on the money withdrawn, the taxpayer would include the untaxed amount in the taxpayer's taxable income. How much incomes taxes the taxpayer pays depends on the taxpayer's specific facts.
The answer also depends on whether the account is a regular IRA or a Roth IRA. With a Roth IRA, if certain conditions are met, even the portion upon which income taxes had not been paid is exempt from income taxes.
You can review Publication 17 for overviews. P17 is free at www.irs.gov . P17 refers to publications on specific tax topics.
In addition to the points raised by Thoung, be aware that if you under 59 1/2 you would also suffer penalties for an early withdraw. There are some exceptions to this rule, but without more facts it is impossible to know if you qualify.
Hope this helps.
Mr. Fromm is licensed to practice law in PA. The response herein is not legal advice and does not create an attorney/ client relationship. The response is in the form of legal education and is intended to provide general information about the matter within the question. Oftentimes the question does not include significant and important facts and timelines that if known could significantly change the reply unsuitable. Mr. Fromm strongly advises the questioner to confer with an attorney in their state in order to ensure proper advice is received.