If you earn 1099 or self-employment income in Delaware, the IRS and the state both expect you to pay taxes as you go, in four quarterly installments rather than one April bill. This calculator estimates your 2026 quarterly payments across all three pieces: federal self-employment tax, federal income tax, and Delaware state income tax. Delaware levies a gross receipts tax on the total revenue of a business, in addition to income tax; self-employed people can owe it on their gross 1099 income. Enter your expected net self-employment income, any W-2 wages, and your filing status to see what to send each quarter, your due dates, and how the safe-harbor rules protect you from an underpayment penalty. Everything is an estimate for planning. Always confirm with the Delaware Division of Revenue before you file.
Self-employment income has no tax withheld for you, so both the IRS and Delaware Division of Revenue ask you to prepay in quarterly installments. On the federal side you owe self-employment tax (15.3% Social Security and Medicare on 92.35% of your net profit, up to the Social Security wage base) plus federal income tax on your profit after the standard deduction. On top of that, Delaware applies its own income tax.
Delaware sets its own threshold for when estimated payments become mandatory; check with Delaware Division of Revenue for the current figure. Heads up: while the schedule below uses the federal dates, Delaware's own first-quarter estimated payment is due April 30 (not April 15). The remaining Delaware due dates (June 15, September 15, and January 15) match the federal ones. Delaware follows the standard four-installment schedule.
You avoid an IRS underpayment penalty by hitting a "safe harbor": paying at least 90% of this year's total tax, or 100% of last year's (110% if your income is higher). Delaware applies graduated rates (2.2% to 6.6%) to your federal AGI after a modest standard deduction ($3,250 single / $6,500 married) and a $110-per-person personal credit that is subtracted from your calculated tax. Single and married filers use the same brackets. Self-employed Delawareans also owe the state's gross receipts tax on business revenue, and those working in Wilmington owe an additional city wage/earned-income tax of about 1.25% that this calculator does not include. You can pay online through the Delaware Division of Revenue portal, and the calculator above breaks your total into the federal and Delaware pieces so you can send each to the right place. You can pay online at the Delaware Division of Revenue (payment portal).
One short email 7 days and 1 day before every federal estimated-tax due date. No account needed; unsubscribe anytime.
For educational purposes only, not tax advice. Tax rules change and individual situations vary; confirm figures with a tax professional and the Delaware Division of Revenue before filing. State tax data last verified 2026-07-06.
Sources: delcode.delaware.gov, revenuefiles.delaware.gov, revenue.delaware.gov.