How to Calculate Quarterly Estimated Taxes as a Freelancer in 2026

I use the annualized method for quarterly estimated taxes because my freelance income refuses to arrive evenly. I collected $4,200 in March and $11,800 in June. Dividing one cheerful annual guess into four equal payments would describe a business I do not have.

I commit to the income that actually arrived in each IRS period.

Through May 31, my books show $18,470 of receipts and $4,286 of expenses, leaving $14,184 of profit. The $11,800 June payment does not belong in that second estimated-tax period because the IRS closes it at the end of May. Nobody tells you this when they call the payments quarterly.

For the period through August 31, I add June, July, and August activity. Receipts reach $46,935 and expenses reach $9,718, so cumulative profit is $37,217. I use profit, not deposits, because the $1,247 printer and $386.42 of software were costs of earning the revenue.

I annualize that eight-month profit by dividing $37,217 by 8 and multiplying by 12. The result is $55,825.50. It is not my promise for December; it is the pace supported by the books today.

I calculate self-employment tax on 92.35% of that annualized profit. My SE base is $51,554.85, and 15.3% produces about $7,888.89 of Social Security and Medicare tax. I use the deductible employer-equivalent half, about $3,944.45, when estimating federal income tax.

Then I apply my filing status, 2026 deduction, tax brackets, credits, household withholding, and payments already made. For the January-through-August annualized period, the Schedule AI calculation uses its cumulative percentage rather than simply asking for three-fourths of a guessed annual bill. Fun system.

I use the calculate your quarterly taxes tool to check the arithmetic, but the annualized method is my decision, not one option in a survey. If I have marketplace coverage, I put the same forecast into the ACA subsidy calculator. That $11,800 June payment can change both estimated tax and a subsidy reconciliation.

I verify the period mechanics in the IRS Form 1040-ES instructions and check the IRS Internal Revenue Bulletin when annual numbers move. State tax gets its own check: I keep the California Franchise Tax Board forms page and New York personal income tax guidance bookmarked rather than pretending the federal worksheet settles both.

Annualizing does not make irregular income predictable. It makes my estimate honest about when I earned it. I save the profit report and payment confirmation together, then use the full FAQ when a deadline looks too strange to trust from memory.