Intergtm

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.

Inputs

Ordinary and necessary costs: software, equipment, travel, home office.

Wages already subject to payroll withholding.

%

Used until the statutory bracket table below is verified.

%

Line for total tax on last year's return. Drives the safe-harbour target.

Results update as you type, and the address bar keeps your numbers so the link you share reopens this exact calculation.

Payment due each quarter

$7,992

Due on each of the four estimated tax deadlines.

Estimated total federal + state tax

$31,967

Detailed results
Self-employment taxCovers both the employer and employee halves of FICA.$14,412
Income tax$17,555
Net business profit$102,000
Safe-harbour annual targetPaying at least this much across the year generally avoids an underpayment penalty.$31,967
Share of revenue to reserve26.64%

What this result means

Payment due each quarter: $7,992.

On this income you should send about $7,992 on each of the four estimated tax deadlines. Your full-year federal and state liability comes to roughly $31,967, which is about 27% 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.
QuarterPayment dueIncome period coveredAmount dueCumulative paid
Q1April 15January 1 - March 31$7,992$7,992
Q2June 15April 1 - May 31$7,992$15,983
Q3September 15June 1 - August 31$7,992$23,975
Q4January 15 (next year)September 1 - December 31$7,992$31,967

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?

Do not rely on generic rules like 25% or 30%, because your actual tax burden depends on your expenses, other income, and state taxes. Instead, use the calculator above to determine your personal *share of revenue to reserve*, then move that percentage into a dedicated tax account every time you invoice payment. This transforms quarterly deadlines from cash-flow crises into a non-event, and ensures you always have enough to pay without scrambling or incurring penalties.

›What is the safe harbour for estimated taxes?

The safe harbour is a threshold that protects you from underpayment penalties, even if your final tax bill exceeds your quarterly payments. You avoid penalties by paying at least a specified percentage of either this year's projected tax or last year's actual total tax—whichever is smaller. For most filers this is 100% of prior-year tax; high-income taxpayers (AGI over $150,000) must pay 110%. The prior-year figure is almost always the better target because it is a known number, whereas this year's tax is a guess.

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

If you expect significant self-employment tax in your first year, you likely owe quarterly payments—there is no prior-year tax to reference for the safe harbour. However, check carefully: if you had W-2 wage income in that year with withholding already paid, that withholding may satisfy the safe harbour requirement even if it was not from self-employment. Run the calculator to estimate your liability and compare it to any existing withholding to determine if quarterly payments are truly required.

›What happens if I miss a quarterly deadline?

The IRS imposes an underpayment penalty computed as interest on the shortfall for each day it was late—not a single flat fee. The longer a payment is overdue, the larger the penalty accrues. If you miss a deadline, pay the shortfall as soon as you notice; every day counts toward the interest calculation. You can also catch up in a later quarter, but the penalty accrues for the earlier quarter's tardiness even after you pay.

›Can business expenses reduce self-employment tax?

Yes, absolutely—and this is a powerful effect. Self-employment tax is calculated on your net profit, so every legitimate business expense reduces the base by which self-employment tax is computed. A $5,000 deduction saves you income tax at your marginal rate plus 15.3% self-employment tax (the combined Social Security and Medicare rate), making the total savings roughly 30–40% of the expense. This double tax effect makes meticulous expense tracking unusually valuable for the self-employed.

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

An S corporation can reduce self-employment tax by splitting net income between a reasonable W-2 salary (subject to ordinary payroll tax) and distributions (which avoid self-employment tax), but the complexity and cost often outweigh the savings at low profit levels. Electing S-corporation status requires separate payroll filings, tax returns, formal accounting, and heightened audit risk if the IRS questions whether your salary is truly reasonable. Most tax professionals recommend this only when self-employment tax savings exceed the incremental accounting and administrative cost—typically $150,000+ in annual profit.

›Do I owe state estimated taxes too?

Most states with an income tax require separate estimated tax payments on their own forms and deadlines, which may differ slightly from federal dates. Some states follow the federal schedule (April 15, June 15, September 15, January 15), while others use different deadlines. This calculator includes a state tax rate as a flat percentage for planning purposes, but it is not a substitute for researching your specific state's estimated payment rules and forms. Check your state's tax agency website for the exact deadlines and filing requirements.

›What if my income is unpredictable?

Always target the prior-year safe harbour when income is lumpy or volatile, because it is fixed and known—no guessing required. This guarantees you avoid penalties as long as you hit that number, regardless of how actual current-year earnings turn out. If your income is highly concentrated (e.g., most revenue lands in Q4), the IRS offers an annualized income instalment method that adjusts each quarterly payment based on what you actually earned through that quarter, potentially reducing early-year overpayment. This requires separate calculation but can improve cash flow when revenue is seasonal.

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