Self Employed Quarterly Taxes

Your self-employed quarterly payment carries two taxes: federal income tax, plus the 15.3% self-employment tax for Social Security and Medicare. A W-2 job splits Social Security and Medicare with an employer. On your own, the full 15.3% is yours — which is why the first invoice you keep in full turns into a bigger tax bill than expected.

Calculate my quarterly number

SE tax + income tax modeled together

Half-SE deduction applied

The Quick Version

When you work for yourself, your quarterly payments have to cover two different taxes: federal income tax, plus the 15.3% self-employment tax on what your business clears.
The IRS expects them once your projected bill for the year tops $1,000, after withholding and credits come off.
The number feels steep because no employer is splitting Social Security and Medicare with you. You pay both halves, then deduct one of them back.

A W-2 employee only ever feels half of this: they pay 7.65% and their employer covers the matching share. Working for yourself, there's no employer to share the load — the whole 15.3% is yours, and your regular income tax comes due as well. Every quarterly payment has to carry both taxes, and that combined weight is what makes self employed quarterly taxes such a shock the first year.

This page is about the calculation — what you owe and why. For the payment system (schedule, set-aside, EFTPS setup), see quarterly taxes for self employed. For penalty avoidance, see safe harbor estimated taxes. See the IRS self-employment tax reference for the primary source.

How the 15.3% Is Built

Two layers of Social Security and Medicare stacked, plus a surcharge above certain income levels:

Social Security: 12.4% (Up to a Cap)

12.4% of net earnings up to the yearly Social Security wage base — $176,100 in 2025, climbing to $184,500 in 2026. Above that cap, this portion stops.

Medicare: 2.9% (No Cap)

2.9% of ALL your net earnings — no cap at all. Every dollar of profit carries this. A further 0.9% Medicare surcharge kicks in once self-employment income crosses $200,000 single or $250,000 married filing jointly.

The 92.35% Small Break

The self-employment tax applies to 92.35% of your profit rather than all of it — so the amount it's calculated on comes in a bit under your actual earnings. Small break, but it lowers the effective rate a touch.

The Half-SE Deduction

You get half of the self-employment tax back as an above-the-line deduction. It cuts your income tax (not the SE tax itself). So you can't just stack the two and call that your total — the income-tax layer sits on top of a slightly-smaller base.

Sizing Your Self Employed Quarterly Taxes

Project the year

We estimate your net Schedule C profit and run both the SE tax and the income tax on it. Legitimate expenses lower profit — and because profit sits under both taxes, a dollar of deduction is worth more to you than to a W-2 employee.

Set the quarterly figure

We add both taxes together and split the total across the four deadlines, so you know exactly what goes out on each date. Concrete: on $80,000 of net Schedule C profit, SE tax applies to 92.35% ($73,880) at 15.3% ≈ $11,304. Half of that (~$5,652) comes back as an income-tax deduction.

Re-check mid-year

If income swings either way, we reset the remaining payments to keep you on track rather than overpaying or falling behind. Once you know the number, paying it on the four dates without missing one is its own system — see <a href="https://dimovtax.com/quarterly-taxes-for-self-employed/">quarterly taxes for self employed</a>.

What Our Clients See

The first number is the scary one. Once expenses and the half-SE deduction are in, it usually comes down to something you can plan around.

$1.5B+

in tax savings identified for clients

63%

of clients return year after year

70+

tax and financial services under one roof

15+ yrs

advising freelancers, contractors, and small business owners

What This Costs

What you pay moves with the work: one income stream is quick, several take longer, and current books speed everything up. Tell us whether you want a single calculation or quarterly support, and we price it after a look at your income and expenses.

Send your income so far and your business expenses. We size the four payments and hand you the number that goes on each date.

One income stream is quick. Multiple streams take longer. Current books speed everything up.

What a Calculator Misses

A calculator multiplies the numbers you feed it. It won't find the expenses that shrink your profit, it won't apply the half-SE deduction in the right order, and it won't net out the Social Security tax already withheld from a W-2 job you also hold.

Missed expenses

The deductions that lower your Schedule C profit sit under BOTH taxes — worth more than a W-2 deduction

Wrong deduction order

Half-SE deduction affects the income-tax layer, not the SE layer itself — order matters

SS cap not shared

If you also have a W-2 job, the Social Security already withheld counts toward the $176,100 cap

Sources: IRS Schedule SE; IRC §1401; SSA wage base updates

When to Calculate the Real Number

A good fit if:

You are new to Schedule C and don't know what percentage to withhold
Your profit is running well above your first-year estimate
You have both a W-2 job and 1099 income and want them modeled together
You crossed $200k (single) or $250k (MFJ) — the Additional Medicare surcharge now applies
You have a spouse who also earns and want the household modeled as one bill

For the payment system (schedule, set-aside, EFTPS), see quarterly taxes for self employed. For penalty avoidance, see safe harbor estimated taxes. Behind on a payment? Missed estimated tax payment is the triage.

Calculate My Quarterly Number

Send us your income so far and your business expenses, and we will size the four payments. Confidential, handled by a CPA — not a call center.

"Taxpayers approach us after doing their taxes in TurboTax or on H&R Block or a do-it-yourself app, and they have a huge tax bill and they don't know why they have it. They don't know even how it came about. They sometimes don't have the money for it."
— George Dimov, CPA, Founder of Dimov Tax

One number back. Both taxes accounted for. The scary number always comes down once expenses and the deduction are in.

Reviewed by George Dimov, CPA

Founder of Dimov Tax

15+ years advising freelancers, contractors, and small business owners on self-employment tax and quarterly payments.