It is at best, an estimate. But it's an estimate that grew drastically more difficult to make under the new law.
The Government Accountability Office estimated in a report last summer that about 30 million workers had too little withheld from their paychecks, which made their take home pay bigger but increased their tax liability. That's about 3 million more workers than normal.
Few taxpayers appear to have heeded the IRS' advice to do a "paycheck checkup" to make sure they had the proper amount withheld. Payroll processor ADP, which is responsible for paying one out of every six Americans, said the vast majority of people in its system didn't update their withholdings last year.
Some taxpayers who did make adjustments found they couldn't get it quite right.
Kevin McCreanor of Milton, Georgia and his wife normally get a sizeable refund each year — it was more than $12,000 last year. While they know waiting for a large refund isn't the best strategy financially, they like a refund and they put anything they get back toward their daughters' education. Their income, earned primarily from his wife's job in telecom, can vary greatly, so there was comfort in never facing a big bill.
The couple increased her paycheck withholdings to ensure the same but found they are only getting back $519 this year. Their income and tax rate did increase, and McCreanor acknowledges there is probably more he could have done to prepare but he is very disappointed all the same.
Some surprises were welcome, however. Brian Goodell and his wife typically face a tax bill of anywhere from $10,000 to $15,000 each year. But this year the Tigard, Oregon, couple is getting a $15,000 refund. They believe they got some benefit from the increased child tax credit. They also made more charitable donations and increased their withholdings. While Goodell isn't entirely sure why it worked out so well, he'll gladly take the refund.
Taxpayers can get a better sense of how they fared by looking at their tax liability or effective tax rate. This information is often available on the summary received from an accountant or tax preparation software. They can also look at the "total tax" on those summaries or form 1040. These are not perfect measures either, but provide some perspective.
And remember that getting a refund is not necessarily a good thing. Breaking even is really the best outcome from an economic point of view. If you get a refund, that means the government has been holding onto your money when you could have been using it.
Additionally, consider that taxes are rarely an equal comparison from year-to-year, said Eric Bronnenkant, the head of tax at Betterment and a CPA and certified financial planner. People's lives change in ways that can dramatically influence their taxes, such as marriages, divorces, kids, moving or job changes. The average taxpayer may not realize the full impact some of these changes might have.
"I am not surprised by the reaction people are having," Bronnekant said. "I think for some people the reaction is more justified than others."