The IRS tax withholding calculator can help you avoid a surprise tax bill next spring, but be sure to run your results by your accountant before you tweak the income taxes pulled from your pay.

That’s because user error and failure to consider your state and local tax loads could lead to you making incorrect adjustments to your withholding.

“There is no question that if you can have some good information about your situation, the calculator will work much better for you and you will get a more accurate readout of where you are,” said Eric L. Smith, a spokesman for the IRS.

“We suggest that once you do it, go in again in a few months and see if you’re current and on target,” he said.

The agency is kicking off a midyear "Paycheck Checkup" initiative on Aug. 13, reminding filers to review the amount of taxes withheld from their pay.

The IRS emphasized that certain households should re-evaluate their withholding, including dual-income families, filers who claim the child tax credit and taxpayers who itemized deductions last year.

This year is particularly interesting: The IRS released its and has put into effect new tax , reflecting changes stemming from the Tax Cuts and Jobs Act.

The new legislation roughly doubled the standard deduction, did away with personal exemptions and trimmed individual income tax rates.

Filers are supposed to use the new withholding calculator to determine what, if any, changes they should make at work to ensure that they’re paying just the right amount of tax at every pay period.

Just make sure you recheck your data with your accountant before you make any changes, tax experts say.

“A lot of people don’t understand the line items and you have to make sure you’re accounting for that accurately,” said certified financial planner Debbie J. Freeman, a CPA and director of financial planning at Peak Financial Advisors in Denver.

“Unless you understand taxes, it’s not something you should fully rely on,” she said.