Quarterly Estimated Tax Calculator: 2026 Self-Employment Tax, Worked

October 19, 2026 · Freelance and creator rates

To work out a quarterly estimated tax payment, take your expected profit for the year, work out self-employment tax on 92.35% of it, add income tax at your own rate on the profit left after deducting half of that self-employment tax, and divide the total by four. In the illustrative example below, $85,000 of 2026 profit carries $12,010.12 of self-employment tax and, at an income tax rate of 15%, a federal total of $23,859.36: $5,964.84 a quarter. The same arithmetic answers the 1099 question of how much to set aside: in this example, 32.72% of every dollar of profit, federal and state together.

The formula

1. Net earnings = net profit x 92.35%
2. Self-employment tax = net earnings x 12.4% (Social Security, up to the wage base) + net earnings x 2.9% (Medicare, no cap)
3. Income tax = (net profit - half of self-employment tax) x your income tax rate
4. Each quarterly payment = (self-employment tax + income tax - any tax withheld from a W-2 job) / 4

The income tax rate in step 3 is your own input, not a bracket table: your real rate depends on your whole return, and none of that is computed here.

Self-employment tax calculator, 2026 figures

The 2026 Form 1040-ES (irs.gov) sets out every figure this step needs. Its self-employment tax worksheet says to “be sure to use only 92.35% (0.9235) of your total net profit from self-employment,” multiplies that by 2.9% for Medicare and by 12.4% for Social Security, and caps the Social Security part: “For 2026, the maximum amount of earned income (wages and net earnings from self-employment) subject to the social security tax is $184,500.” IRS Publication 505 (2026) adds a floor: if 92.35% of profit is under $400, there is no self-employment tax to compute.

On an illustrative $85,000 of net profit, with no W-2 job:

That is 14.13% of profit, not the headline 15.3%, because only 92.35% of profit is taxed. The Social Security part would stop growing once net earnings pass the $184,500 wage base, which takes about $199,783 of profit with no wages; a W-2 job uses up part of the wage base first. The 1040-ES worksheet treats half the self-employment tax, $6,005.06 here, as “your expected deduction for self-employment tax on Schedule 1 (Form 1040),” which is why step 3 subtracts it.

Worked example: the quarterly payment

Same $85,000 of profit, an income tax rate of 15% and a state rate of 5%. Both rates are illustrative inputs, not anyone’s actual rate.

Each federal payment: $23,859.36 / 4 = $5,964.84. If your state taxes this income and collects quarterly, it is a separate payment with its own rules; at the example’s 5% that is $987.44 a quarter. Federal and state together come to $27,809.11, or 32.72% of profit.

The 2026 Form 1040-ES gives four due dates: April 15, 2026, June 15, 2026, Sept. 15, 2026 and Jan. 15, 2027. The last one can be skipped “if you file your 2026 tax return by Feb. 1, 2027, and pay the entire balance due with your return.” The periods behind them are not equal lengths, so the June payment arrives soon after the April one.

How much to set aside for taxes on 1099 income

The habit that makes the quarterly payment painless is moving a fixed share of every payment into a separate account as it comes in. Below the wage base, the self-employment rate is flat, so one percentage works for every invoice:

The income and state lines are multiplied by (1 - half the self-employment rate) because of the half-SE deduction. Checked the other way, the year’s federal and state tax of $27,809.11 on $85,000 of profit is the same 32.72%.

That rate applies to profit, not to the whole payment. Take an illustrative $2,400 payment from a client, and say 15% of your revenue goes on business costs. Profit in it is $2,040.00, so the set-aside is $667.42, which is 27.8% of the payment, and $1,732.58 is yours to run the business and live on. A round 33% of profit is easier to remember and leaves a small cushion. Above the wage base the 12.4% part stops, and the flat rate overstates what you need.

The insight: the payment the IRS requires can be smaller than the tax

The $5,964.84 above is what pays the year’s tax in four equal parts. It is not necessarily what you have to pay to avoid an underpayment penalty. The 2026 Form 1040-ES General Rule protects you if your payments and withholding are at least the smaller of “a. 90% of the tax to be shown on your 2026 tax return, or b. 100% of the tax shown on your 2025 tax return,” and “if your adjusted gross income (AGI) for 2025 was more than $150,000”, you substitute 110% for 100%. Estimates are required at all only if you “expect to owe at least $1,000 in tax for 2026”.

Say the example’s 2025 return showed $18,000 of total tax, on an AGI of $160,000. That AGI is over the line, so the prior-year rule is 110%: $19,800.00. The current-year rule is 90% of $23,859.36, which is $21,473.42. The smaller one sets the requirement, so $4,950.00 a quarter meets the rule, $1,014.84 a quarter less than the full share. The other $4,059.36 is still owed; it is paid with the return. Safe harbor moves when you pay. It does not lower the tax, which is why the set-aside habit matters even when the quarterly payment is the smaller figure.

When the income comes late in the year

If a large share of a year’s profit lands late, equal quarters ask for money before you have earned it. IRS Publication 505 (2026), Worksheet 2-9, lets you annualize instead: profit to the end of each period is multiplied up to a full year (by 4 for the first period, then 2.4, 1.5 and 1), taxed, and a growing share of that tax (22.5%, 45%, 67.5%, 90%) is due by each date, never more than the regular installment plus anything carried forward. Here the same $85,000 year arrives unevenly:

With $8,000 earned by March 31, the April payment drops from $4,950.00 to $2,021.03, $2,928.97 less, and the later payments catch up. If you use this method, the IRS asks for Form 2210 with Schedule AI on your return.

How these were calculated

Self-employment tax follows the 2026 Form 1040-ES worksheet as described above, with the $400 floor from IRS Publication 505 (2026). Income tax is profit less half of self-employment tax, times a flat rate you choose; no brackets, standard deduction or qualified business income deduction are computed. The safe-harbor rules and due dates are quoted from the 2026 Form 1040-ES; the annualized payments follow Publication 505 (2026) Worksheet 2-9, with your flat rate in place of the bracket lines and no W-2 wages. The 0.9% Additional Medicare Tax and the underpayment penalty itself are not computed.

Every figure on this page was computed twice, once by the code behind the calculator pack below and once by a separate implementation written from the formulas, and the two agree to the cent. The profit, rates, invoice, cost share, prior-year tax and AGI are illustrative, not typical figures for anyone. None of this is financial, legal or tax advice; for your own payments, a tax professional and the IRS instructions are the authorities. If you are weighing a contract against a salary, the W-2 to 1099 rate calculator shows how self-employment tax feeds into the rate you charge, and the freelance hourly rate calculator builds the tax set-aside into an hourly price.

If you want to run this on your own year, including the Additional Medicare Tax and a payment calendar that says whether you are behind, the pack below does it in linked spreadsheets with every formula visible.