Calculators

Quarterly estimated tax, for 2026.

Federal, state and self-employment tax on a net profit, a job, and what was already withheld. The four payments below, with dates. The same arithmetic the app runs on a real ledger, run here on the numbers you type.

Contha keeps your personal and business money in one set of books and works this out as money lands. From $5 a month, with a free week first.

Your situation

Nothing typed here leaves your browser. The figures on the right recompute as you type.

Filing statusState

Expected net profit from self-employmentThis year, after business expenses. What Schedule C would show as profit.W-2 wagesFrom a job, this year. Box 1, or what it will be by December.Federal tax withheldBox 2 on that W-2. Counts toward the four payments below.Other ordinary incomeA K-1 share, interest, anything else taxed as ordinary income. No self-employment tax on this.Estimated payments already made this yearOptional. What you have sent the IRS for 2026 so far. Leave blank and past dates read as what would have been due.

Estimated 2026 tax

12.0% marginal

Net profit$60,000.00

Self-employment tax15.3% on 92.35% of net profit$8,477.73

Federal income tax$3,559.47

State income taxChoose a state above.

Total tax$12,037.20

Effective rate20.1%

The four payments

$8,125.11 would have been due for Q1, Q2 and Q3 by now. If you have paid nothing, pay that now: the IRS charges interest on a late quarter from its date, so sooner costs less. Enter what you have paid to see exactly what is left.

Q1Apr 15, 2026Running total $2,708.37

$2,708.37date passed

Q2Jun 15, 2026Running total $5,416.74

$2,708.37date passed

Q3Sep 15, 2026Running total $8,125.11

$2,708.37date passed

Q4Jan 15, 2027Running total $10,833.48

$2,708.37due

The four add up to $10,833.48, not the $12,037.20 total: paying 90% of this year’s tax on time is what keeps the penalty off, and the rest is due with the return in April. A quarter of 90% of this year’s tax, each date, after withholding. Add last year’s total tax in the app and this becomes the full safe-harbor test: the lesser of that and 100% (110% above $150,000) of what you owed last year.

How this is computed

Self-employment tax on 92.35% of net profit: 12.4% Social Security up to the wage base, plus 2.9% Medicare.
Half of that self-employment tax deducted back above the line, before federal tax is figured.
A 20% qualified business income (QBI) deduction on what's left, the same as the return allows.
The single standard deduction, on the federal side.

An estimate of what to set aside, not a filed return. It excludes itemized deductions, retirement contributions and credits.

On your real books

Contha runs this same engine on your actual transactions.

Connected accounts instead of typed guesses, a reserve that says whether the tax money is really there, the four payments recorded as you send them, and a year-end package your accountant opens without an account.

Start a free week

On Business, $10 a month after, no card to start.

The why behind the number: quarterly taxes for freelancers, self-employment tax, safe harbor.