Quarterly Tax Calculator
Updated August 2026 · Free · No sign-up
Calculate quarterly estimated taxes for freelancers and 1099 contractors — self-employment tax plus income tax, split into the four IRS payment deadlines, with the safe-harbor rules that kill penalties.
Quick answer: Set aside 25-30% of net self-employment income for federal taxes. Quarterly payment ≈ (net profit × 14.13% SE tax + net profit × your income tax bracket) ÷ 4. Deadlines: April 15, June 15, September 15, January 15.
The Two Taxes You Are Prepaying
- Self-employment tax: 15.3% on 92.35% of net profit (= 14.13% effective) — Social Security to the annual wage base + Medicare uncapped. Half of it is deductible against income tax.
- Income tax: your bracket rate on profit minus the SE-tax deduction minus your standard/itemized deduction.
No employer withholds these for you — the IRS wants them across the year, hence quarterlies.
Worked Example
$90,000 net profit, 22% bracket, $15,000 standard deduction, 5% state:
| SE tax | $90,000 × 92.35% × 15.3% = $12,717 |
| Income tax base | $90,000 − $6,359 (half SE) − $15,000 = $68,641 |
| Federal income tax (approx.) | ~$10,500 (blended through brackets) |
| State (5%) | ~$3,400 |
| Total ≈ $26,600 → quarterly ≈ $6,650 | ~30% of profit |
The Deadlines (Uneven on Purpose)
| Quarter covers | Payment due |
|---|---|
| Jan 1 – Mar 31 | April 15 |
| Apr 1 – May 31 (2 months!) | June 15 |
| Jun 1 – Aug 31 | September 15 |
| Sep 1 – Dec 31 (4 months) | January 15 (next year) |
Q2 is only two months of income — budgeting four equal payments across uneven periods is why June surprises new freelancers.
Safe Harbor: The Penalty Kill Switch
You owe no underpayment penalty if your total payments reach either: 90% of this year's tax, or 100% of last year's tax (110% if last year's AGI exceeded $150k). The practical strategy for volatile income: pay 100/110% of last year's number in four equal installments and settle the difference at filing — fully penalty-proof regardless of how this year explodes. First profitable year with no prior-year tax? The prior-year safe harbor is $0 — technically penalty-free, but save anyway or April will hurt.
Payment Mechanics and Habits
- Pay online: IRS Direct Pay or EFTPS — takes minutes, no vouchers.
- The percentage habit: move 25-30% of every client payment into a separate tax account on receipt — the single behavior separating calm freelancers from April-panic freelancers.
- Recalculate mid-year: rerun this calculator after big quarters; the annualized-income method lets uneven earners match payments to actual income (Form 2210 Schedule AI).
- Reduce the bill legitimately: Solo 401(k)/SEP contributions, health insurance deduction, QBI deduction, and honest expense tracking all shrink the quarterly number — the rate-setting side of this lives in the freelance rate calculator.
Who Must Pay Quarterlies?
Anyone expecting to owe $1,000+ beyond withholding: freelancers, 1099 contractors (see W-2 vs 1099), gig workers, landlords with significant net income, and W-2 employees with large side income (alternative: raise your job's withholding via W-4 to cover the side income — withholding counts as paid evenly all year, a useful catch-up trick in Q4).
Frequently Asked Questions
How much should I set aside for quarterly taxes?
25-30% of net self-employment profit covers federal SE tax plus income tax for most freelancers in the 22% bracket; add your state rate on top.
When are quarterly taxes due?
April 15, June 15, September 15, and January 15 — note the uneven periods: the June payment covers only April-May.
What is the safe harbor rule?
No penalty if you pay 90% of this year's tax or 100% of last year's (110% if prior AGI over $150k). Paying last year's number in four installments is penalty-proof.
What happens if I miss a quarterly payment?
An underpayment penalty accrues like interest on the shortfall from its due date — pay as soon as possible; the penalty stops growing when you do.
Do I pay quarterly taxes in my first freelance year?
If you had no prior-year tax liability, the safe harbor is technically $0 — but the full bill still lands in April, so save the 25-30% regardless.
Can W-2 withholding cover my side income?
Yes — increasing job withholding via W-4 counts as paid evenly through the year, which can retroactively cover earlier quarters of side income.
✓ Formula verified • Last updated: August 20, 2026