Self-Employment Quarterly Tax Estimator

Work out what to send the IRS each quarter on freelance or 1099 income, including self-employment tax and the safe-harbour target that avoids penalties.

Payment due each quarter

$5,610

Due on each of the four estimated tax deadlines.

Estimated total federal + state tax

$22,440

Detailed results
Self-employment taxCovers both the employer and employee halves of FICA.	$0.00
Income tax	$22,440
Net business profit	$102,000
Safe-harbour annual targetPaying at least this much across the year generally avoids an underpayment penalty.	$22,440
Share of revenue to reserve	18.7%

What this result means

On this income you should send about $5,610 on each of the four estimated tax deadlines. Your full-year federal and state liability comes to roughly $22,440, which is about 19% of gross revenue — reserve that share of every payment you receive and the quarterly dates stop being a cash-flow shock.

Quarterly payment schedule

Each estimated tax deadline for the year, the amount due, and the cumulative total paid toward your safe-harbour target.

Quarterly payment schedule. 4 rows, first 4 shown.
Quarter	Payment due	Income period covered	Amount due	Cumulative paid
Q1	April 15	January 1 - March 31	$5,610	$5,610
Q2	June 15	April 1 - May 31	$5,610	$11,220
Q3	September 15	June 1 - August 31	$5,610	$16,830
Q4	January 15 (next year)	September 1 - December 31	$5,610	$22,440

How this is calculated

se_tax = net_profit x 0.9235 x (social_security_rate + medicare_rate)
income_tax = (net_profit + w2_income - se_tax/2 - standard_deduction) x marginal_rate
quarterly = (min(safe_harbor_targets) - w2_withholding) / 4

Why self-employment changes the arithmetic

An employee splits Social Security and Medicare with their employer and never sees the employer's half. Working for yourself, you pay both halves as self-employment tax, computed on a statutory fraction of net profit and layered on top of ordinary income tax. This is the single largest reason freelancers underestimate their bill: someone moving from a salary to equivalent 1099 revenue owes materially more tax on the same headline income.

Half of the self-employment tax is deductible when computing adjusted gross income, which softens the blow slightly. This calculator applies that adjustment before figuring income tax.

Profit, not revenue

Tax is owed on net profit — revenue minus ordinary and necessary business expenses. Every legitimate deduction you fail to track is money handed over unnecessarily. Software subscriptions, professional insurance, a proportional home-office deduction, mileage, hardware, and continuing education are all commonly missed. The Share of revenue to reserve output converts your result into a simple rule of thumb: transfer that percentage of every invoice into a separate account the day it lands, and quarterly payments stop being painful.

The safe harbour is the real target

The tax authority does not require you to predict your income perfectly. It requires you to pay enough, on time, to land inside a safe harbour: either a percentage of the current year's tax or a percentage of last year's total tax, whichever is smaller. High-income taxpayers face a higher prior-year percentage.

Meeting the prior-year safe harbour is the practical choice for anyone with volatile income, because last year's tax is a known number while this year's is a guess. Pay a quarter of the target on each deadline and a strong year cannot generate a penalty, however large the final balance turns out to be.

Four deadlines, not four equal quarters

The estimated tax periods are famously uneven — the "quarters" do not each span three months. This calculator divides the safe-harbour target evenly, which is correct if your income arrives steadily. If your revenue is lumpy, for example a single large project in the autumn, the annualised income method lets you pay in proportion to when you actually earned it and can prevent an early-year overpayment.

What raises the number

Adding W-2 income to the picture matters in two directions. Wages consume part of the Social Security wage base, reducing the Social Security portion of your self-employment tax. But withholding on those wages also counts toward your total payments, so entering it reduces what you need to send each quarter. If you or a spouse have salaried income, deliberately over-withholding there is often simpler than making four separate payments — withholding is treated as paid evenly across the year regardless of when it occurred.

Assumptions

Income is reported on Schedule C as a sole proprietor or single-member LLC; S-corporation salary splits are not modelled.
Federal income tax uses the marginal rate you enter rather than the full bracket table.
The standard deduction is assumed; itemised deductions, credits, and the qualified business income deduction are excluded.
Statutory rates, wage base, deduction amounts, and safe-harbour percentages are placeholders until verified against the cited IRS and SSA sources.
Income is assumed to be earned evenly across the year, so the four payments are equal.
State tax is a flat rate on adjusted gross income with no state-specific rules.

Frequently asked questions

›How much should I set aside for taxes as a freelancer?

Rather than using a generic percentage, run your own numbers and use the share-of-revenue output above. Move that percentage of every payment into a dedicated account as it arrives so the quarterly deadline never requires finding cash.

›What is the safe harbour for estimated taxes?

You generally avoid an underpayment penalty by paying either a set percentage of the current year's tax or a set percentage of the prior year's total tax, whichever is less. The prior-year figure is easier to hit because it is already known.

›Do I have to make quarterly payments in my first year of self-employment?

If you expect to owe more than a small threshold when you file, yes. With no prior-year self-employment tax, the prior-year safe harbour may already be satisfied by withholding from earlier wage income, so check both routes.

›What happens if I miss a quarterly deadline?

The penalty is calculated as interest on the shortfall for the period it was late, not a flat fine. Paying as soon as you notice limits the cost, and catching up in a later quarter reduces but does not fully erase the charge.

›Can business expenses reduce self-employment tax?

Yes. Self-employment tax is computed on net profit, so every legitimate deduction reduces both income tax and self-employment tax. That double effect makes disciplined expense tracking unusually valuable.

›Should I form an S corporation to lower self-employment tax?

An S corporation can reduce self-employment tax by splitting income between reasonable salary and distributions, but it adds payroll filings, accounting cost, and audit scrutiny over what counts as reasonable. It typically only makes sense above a meaningful profit level.

›Do I owe state estimated taxes too?

Most states with an income tax require their own estimated payments on separate forms, sometimes on a different schedule. The state figure here is a flat-rate approximation, not a substitute for your state's rules.

›What if my income is unpredictable?

Target the prior-year safe harbour, which is fixed regardless of how the current year develops. If income is heavily concentrated in one part of the year, the annualised income instalment method lets payments follow actual earnings.