My husband and I are married and file jointly. We are both teachers and claim 0 dependents. Last year we owed $12,000 which was crazy! I used the online calculator to see how much we needed to withhold from our checks. This year we were still going to owe $6,000. What are we doing wrong and how do we fix it? I am fine breaking even, but don't want to owe thousands of dollars every April. Thanks!
If all of your income is reported on W-2s, then you should be close to breaking even by claiming Married with zero exemptions on your W-4 filed with your employers. The withholding tables are meant to work that way.
If you have adjusted your withholdings and you still have a large balance due, then you need to take a look at your other sources of income that may not have any taxes being withheld. For example, if either of you has a self-employed business generating income, then you may need to make estimated payments to cover the income tax and self-employment tax on that income.
Another example would be investment income, such as capital gains. This type of income does not normally have income tax withheld and a large gain can increase your taxes.
Without being able to see your return and know what types of income and deductions you are reporting, this is just some possible examples. But if your withholdings are correct and your income is from W-2s, then it is not typical to have such as large balance due. You may benefit from having a local tax preparer review your returns or from verifying that your W-2 entries are accurate.