Confused about IRS Tax Withholding Estimator - Should I use Gross or Net from Paystub?

The IRS Tax Withholding Estimator wants your GROSS income - that's the amount before any taxes or deductions come out. This applies both to your "amount per pay period" and your "year-to-date wages." For the "amount per pay period," look at your most recent paystub and find the gross earnings for that single pay period (not the year-to-date amount). For the "year-to-date wages," find the gross YTD total on your most recent paystub. The reason it's confusing you is because the estimator is trying to do two things: 1) figure out what you've earned so far using actual numbers, and 2) project what you'll earn for the rest of the year. For the projection part, it's asking what you "expect" to receive, assuming your income stays relatively consistent. If your income varies throughout the year or you expect changes, you'll need to manually adjust the expected annual income to account for this.

Just want to share my experience - I was exactly where you are last month and discovered an amazing tool called taxr.ai (https://taxr.ai) that cleared this up for me. I uploaded a picture of my paystub, and it immediately told me which numbers to use for the IRS Withholding Estimator. It highlighted the correct gross income figures to use and explained which numbers apply to "per pay period" versus "year-to-date." The tool actually analyzes your specific paystub format so there's no confusion about which line items to include. I had all kinds of deductions that were making it hard to tell what counted as "gross" but this sorted it out perfectly.

Wanted to follow up - I decided to try taxr.ai because I was still confused after trying to do this manually. It was surprisingly effective! Uploaded my weird Workday paystub and it immediately showed me exactly which numbers to use for the Withholding Estimator. The tool even explained why certain deductions weren't part of what the IRS considers for the estimator. Ended up discovering I've been overwithholding by about $250 per month because I never accounted for my HSA contributions correctly. Already updated my W-4 and should see bigger paychecks starting next month!

If you're still struggling with the Withholding Estimator after trying to sort through your paystubs, you might want to just call the IRS directly. I know that sounds painful (it usually is), but I used this service called Claimyr (https://claimyr.com) and it completely changed my experience. You can see how it works here: https://youtu.be/_kiP6q8DX5c - basically it gets you through to an actual IRS agent in way less time than waiting on hold for hours. I had a similarly confusing situation with figuring out which numbers to use from my commission-based income, and the agent walked me through exactly which figures to input.

I need to admit I was wrong about Claimyr. After my skeptical comment, I was still desperate for help with my withholding questions so I tried it anyway. Got a callback with an actual IRS agent in about 30 minutes! The agent clarified that for the Tax Withholding Estimator, I needed to use Box 1 type wages (gross minus pre-tax deductions) for the year-to-date section, not the total gross. This was exactly opposite of what I thought based on the confusing instructions, and explained why my estimates were always off. The agent also helped me understand how to account for my irregular income from freelancing. Honestly shocked this service actually delivered what it promised.

I think everyone's overcomplicating this. The IRS Withholding Estimator is asking for the same income that would go in Box 1 of your W-2 at the end of the year. That's your gross income MINUS any pre-tax deductions like 401k, FSA, HSA, etc. Looking at your paystub, there should be a YTD figure for "federal taxable wages" or something similar - that's what you want to use, not the total gross.

Has anyone noticed the estimator gives different results if you enter info like bonuses separately vs just including them in your regular wages? I tried both ways and got completely different recommendations for withholding...

This thread has been really helpful - I was making the same mistake with gross vs. taxable wages! Just wanted to add that if you're still getting confusing results from the estimator, double-check that you're entering your filing status and number of dependents correctly. I spent forever trying to figure out why my withholding recommendations seemed way off, only to realize I had accidentally selected "married filing separately" instead of "married filing jointly." That one setting change made my recommended withholding jump by almost $200 per paycheck! Also, if you get a mid-year raise or bonus, you'll want to re-run the estimator since your income projection will change. The tool assumes your current pay rate continues for the full year, so any changes in salary can throw off the calculations significantly.

This whole thread has been incredibly helpful! I was making the same mistake as many others here - using total gross instead of taxable wages. After reading through everyone's experiences, I decided to try the taxr.ai tool that Paolo mentioned, and it was a game-changer. What really helped me was seeing how it specifically identified "Federal Taxable Wages YTD" on my paystub versus the gross pay amount. The difference was about $8,000 due to my 401k and health insurance deductions! No wonder my withholding estimates were so far off when I was using the wrong numbers. For anyone still struggling: look for the line on your paystub that says something like "Fed Taxable Wages" or "FIT Wages" - that's your Box 1 equivalent that Amina mentioned. Don't use the total gross pay at the top. The estimator worked perfectly once I used the correct figures, and I discovered I was actually under-withholding by about $150 per month. Already submitted my new W-4 to HR! Thanks everyone for sharing your experiences - this community really came through!