Quarterly Estimated Tax Payment Calculator

Taxes are complex. You know what else is complex? Being a therapist. You simultaneously track a client’s history, the systems bearing down on them, your own countertransference, and the actual words coming out of their mouth, AND THEN moosh all of it together (scientific term) to spot patterns, pick interventions, and guide them toward their goals. All while maintaining full therapeutic presence and embodied engagement. If you can do THAT, sweet baby jeebus, you can figure out your quarterly estimated taxes.

Math is hard, especially for us touchy-feely-brained types. Use the calculator below to make it easier. A few things before you dive in: This tool is built for straightforward tax situations. If you’ve under or overpaid in previous quarters, it won’t tell you that. It’s just looking at this quarter right here and now. If you’re planning to itemize, have other income streams, are over 65, or your situation is complicated in some other special way, this isn’t your calculator. Go find a CPA.

**Important: Don’t forget to pay your quarterly estimated state taxes as well. This calculator just does the federal bit.

Disclaimer: This is an estimate (it’s in the name). And dammit, man, I’m a therapist, not a tax wizard. If you want certainty around taxes, talk to a CPA. Don’t sue me please.

FAQ About Quarterly Estimated Taxes

Where do I go to pay these taxes?

You can pay your federal taxes here. If you’re in NC, you can pay your state taxes here. (FYI: the tax rate in NC is 3.99% for 2026.) If you’re in another state, Google that junk or ask your favorite AI overlord.

What happens if I don’t pay quarterly?

The IRS will hunt you down and put your whole family in jail. No, they won’t. They’ll just charge you a penalty fee. If you ignore the quarterly stuff and instead pay annually when you file your tax return, the IRS misses out on a bunch of sweet, sweet interest they could be earning off your tax money throughout the year. That makes the snakes in their brains angry, so they punish you by charging a 6-8% penalty.

The good news is that the snakes in the IRS agents’ brains can be soothed without money by simply calling them on the telephone, promising you’ll never make that mistake again, and asking them to waive the fee. They’ll usually do it once. But if you call and say the same thing the next year, they will absolutely kidnap your family and put them in jail.

What happens if this calculator is a piece of crap and I end up paying the wrong amount in quarterly taxes?

Let me remind you that these are “estimated” quarterly taxes. The IRS does not expect you to get it right down to the penny. When you file your tax return next year, you’ll put on there how much you paid in estimated taxes each quarter this year. Then whatever tax software you use (or your accountant uses) will do a bunch of complex math to determine how much you under- or over-paid by.

If you over-paid, you’ll get a tax refund. Sounds great, but that means you basically gave the government an interest-free loan of that amount. It won’t cause you any problems, but it’s not the most financially savvy idea.

If you under-paid, you may have to pay penalties and interest. You’ll start by seeing if you’re covered by the safe harbor rule (see next question below). If you underpaid by so much that you’re not covered by the safe harbor rule, you might be able to get a break on the penalties and interest by calling the IRS and begging for forgiveness. Sometimes they can find a way to cut you a break.

Worst case scenario, they’ll charge you a penalty based on the amount of the underpayment, how long that money has been owed, and a 6-8% interest rate. The calculation involved is too complex for my tiny brain to understand, but it can be a significant chunk of change. I once knew someone who didn’t pay taxes at all for a few years while making good money. When the IRS caught up with them, they owed so much that they lost their home and car and had to live under severe financial stress for several years while they worked to repay what they owed. Pay your taxes, friends!

What is the safe harbor rule?

The safe harbor rule says that if you accidentally calculate wrong and underpay your taxes, you’ll have to pay whatever additional taxes you owe but you won’t get charged a penalty if:

• you paid the same amount in taxes this year as you paid last year (or 110% of last year’s amount if you’re high income)
• you paid at least 90% of the taxes you owe for this year (meaning you have wiggle room of up to 10% in your calculations)
• you owe less than $1,000 in taxes
• the underpayment was due to a federally declared disaster

A simple example is if you paid $10k in taxes last year and you paid the same amount this year but you actually should have paid $12k this year, you’ll have to pay the extra $2k but you won’t have to pay a penalty fee.

Tax brackets… are… a thing. But really what are they?

Let’s call them buckets instead of brackets. Imagine these buckets on a set of stairs. When the top bucket fills up, it falls over and starts filling up the next bucket, which then does the same thing to the next bucket, etc. The buckets have different labels depending on if you’re single, head of household, or married. Look at the table below, choose the appropriate column for yourself, and label your buckets with the max amount in each box in your column.

Let’s use all the single ladies as an example. For them, the top bucket is labeled $12,400. They’ll pay 10% (from the tax rate column) on any income that falls into that bucket. When that bucket is full, they’ll move on to the second bucket, which labeled $50,400. They’ll pay 12% on any income in that falls into bucket. The third is $105,700. They’ll pay 22% for the income in that bucket. And on down the line.

Let’s say this amazing single lady makes a net income after all expenses and deductions of $110,000 in 2026. Her taxes will look like this:

• Bucket 1: 10% of $12,400 = $1,240
• Bucket 2: $50,400 – $12,400 (in the first bucket already) = $38,000. 12% of that = $4,560
• Bucket 3: $105,700 – $50,400 = $55,300. 22% of that = $12,166
• Bucket 4: $110,000 – $105,700 = $4,300. 24% of that = $1,032
• Grand total = $1,240 + $4,560 + $12,166 + $1032 = $18,998

But wait, there’s more! That’s just her income taxes. If she’s self-employed, she also has to pay self-employment tax of 15.3%.

We have to pay self-employment taxes on top of our income taxes?

Yes, but listen. When you’re an employee, you pay 7.65% of your income toward Social Security and Medicare, and your employer pays an additional 7.65% for you. That’s a total of 15.3%. When you’re self-employed, you pay the full 15.3% (12.4% to Social Security and 2.9% to Medicare). BUT you get to deduct half of that from your income. So if you owed $10k in self-employment taxes, you would get to subtract $5k from your total income to reduce your tax burden.

Also, only 92.35% of your net earnings from self-employment is subject to self-employment tax. Why? I don’t know. Because the tax gods said so.

And we have to pay state taxes too?

Yes, you pay both federal estimated taxes and state estimated taxes. The state part is usually easy. In NC, the state tax rate is a flat 3.99% for 2026. So take your gross income and subtract all your expenses and deductions to get your net income. Then multiply that amount by .0399. Then pay that amount to the state. Done.

Why are taxes so much more for self-employed people?

Because you get to choose your hard.

You can go get a regular job and they’ll make your life easy by calculating all this stuff and paying some of your taxes for you. They may also give you health insurance, paid time off, a 401k, and other benefits. But you often have to trade freedom and autonomy for that. Regular jobs usually come with lots of rules about schedules, time off, job duties, and lots of other stuff. They may also come with shitty managers and a toxic company culture.

The alternative is to work for yourself and have the freedom to do everything exactly how you want. The only rules are whatever rules you give yourself. But then you’ve got to figure out all this tax stuff yourself (or pay someone to do it) and pay a bit more in taxes. You also may not get health insurance or other benefits.

Choose wisely. And remember, you can always change your mind.

What the hell makes a therapist qualified to create a tax calculator?

I make no claims about being qualified to do much of anything, but back when dinosaurs roamed the earth, I worked for an accounting firm as an admin/tax assistant. During that time, I calculated and filed tons of peoples’ quarterly estimated taxes. I was never a CPA. I was simply a trained monkey pushing the same few buttons on a computer over and over again. This is how I know that just about anyone who really wants to can figure this out.

Have more questions?

Reach out to me here. Like a typical therapist, I love helping people. Send me your questions and I’ll do my best to help.

WRITTEN BY

Jennifer Carragher

I’m an online therapist who specializes in trauma (especially betrayal trauma) and works with folks throughout North and South Carolina. My mission is to help people move on from the shitshow that is abuse and trauma, toward a more fulfilling, meaningful life.