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Four payments a year. Zero April panic.
Freelancers owe taxes as they earn, not in April — the IRS expects four estimated payments, and underpaying costs penalties even if you pay in full at filing. This calculator combines self-employment tax and income tax (2026 brackets, standard deduction, and the SE-tax deduction built in) into a quarterly payment, and shows the safe-harbor alternative based on last year's tax.
Every 1099 worker four times a year: it combines SE tax and income tax into the actual payment, and the safe-harbor line tells penalty-worriers the minimum that keeps them clean. Accountants point clients at it instead of explaining 1040-ES over the phone.
On $90,000 of profit filing single in 2026: SE tax is $12,716.60, income tax after the standard deduction and half-SE deduction is $9,571.17, total $22,287.77 — about $5,571.94 per quarter. If last year's total tax was lower, the safe-harbor rule (100% of prior-year tax, 110% over $150k AGI) may let you pay less without penalty.
April 15, June 15, September 15, and January 15 of the following year. Note the quarters are uneven — the June payment covers only April and May. Pay via IRS Direct Pay or EFTPS; keep confirmation numbers.
The IRS charges an underpayment penalty (interest at the federal short-term rate plus 3 points) for each quarter you were short — even if you pay everything by April. The safe-harbor rule is the escape hatch: 100% (or 110%) of last year's tax, paid evenly, avoids the penalty regardless of this year's bill.