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How to Estimate Quarterly Taxes as a Freelancer

By the ClearRate team · Updated November 2026 · 5-minute read

Nobody withholds tax from freelance pay, so the IRS asks you to do it yourself — four times a year, in advance. This guide explains who has to pay, how much is enough, when the money is due, and what happens if you get it wrong.

Who must pay quarterly?

The rule is straightforward, even if the details are not. If you are self-employed in the United States and you expect to owe at least $1,000 in tax for the year, after withholding and credits, you are generally expected to pay estimated tax in quarterly installments. That covers most full-time freelancers. It also covers part-time freelancers whose side income is large enough to leave a bill of $1,000 or more, and anyone with income that has no withholding at all — rental income, for example, or a business with no employees.

The $1,000 threshold is about the tax you will owe, not the income you earn. When in doubt, estimate the tax — the quarterly tax estimator does the arithmetic — and if the annual total is above $1,000, plan on paying quarterly.

How much should you pay each quarter?

The honest answer is one quarter of the tax you will owe for the whole year. The practical problem is that you do not know the whole year’s income in April. The usual method is to estimate your annual income, work out the annual tax, and divide by four. If your income is steady, that works well: each quarter looks like the last, and each payment is about the same. If your income jumps around — a big project in the spring, a quiet summer — the equal-quarters method can leave you overpaying in slow quarters and underpaying in busy ones. In that case, estimate each quarter from that quarter’s actual income instead, using the annualized income method the IRS provides on Form 1040-ES. It is more work, but it matches the payment to the income that produced it.

What goes into the estimate? Three parts. Federal income tax, charged on your net income at your marginal rate — the rate on your last dollar of income, which depends on your total annual income and filing status. Self-employment tax, 15.3 percent for Social Security and Medicare on 92.35 percent of net self-employment income, which applies even when your income tax is low. And state income tax, if your state has one. A freelancer in the 22 percent federal bracket with a 5 percent state rate, earning $20,000 net in a quarter, would owe about $4,400 in federal tax, $2,825.91 in self-employment tax, and $1,000 in state tax — $8,225.91 for the quarter. The worked example on the quarterly tax estimator page walks through that exact calculation. The self-employment tax is the part people underestimate most: it is more than a third of the total, and it is charged on income that may owe little or no federal income tax.

The safe harbor: how much is enough?

The IRS does not expect a perfect estimate. It expects a good-faith one, and it defines good faith with a rule called the safe harbor. If you pay at least 90 percent of this year’s tax, or 100 percent of last year’s tax, you will generally avoid the underpayment penalty even if your estimate turns out to be low. The 100 percent figure rises to 110 percent of last year’s tax if your adjusted gross income was above $150,000 ($75,000 if married filing separately). You can use whichever of the two tests is easier for you.

Last year’s tax is usually the simpler test, because it is a known number. If you owed $12,000 in tax last year, pay $3,000 a quarter this year and you are inside the safe harbor, even if this year turns out to be much better and you owe $16,000. You will still owe the extra $4,000 when you file, but you will not owe a penalty on it. This year’s 90 percent test is the better choice when your income has fallen. Pay in equal quarterly installments — the safe harbor generally requires the payments to be spread across the year, not paid in a single lump at the end.

Due dates — and why the quarters are uneven

Estimated tax is due four times a year, and the dates are easy to remember once you know the pattern: April 15, June 15, September 15, and January 15 of the following year. The quarters themselves are not equal. The first covers January through March, the second April and May, the third June through August, and the fourth September through December. The June payment comes only two months after the April one, which catches people out every year: two payments in two months, right after the annual tax return is due. If a due date falls on a weekend or a holiday, it moves to the next business day, so check the current year’s dates rather than assuming.

The underpayment penalty, in plain terms

If you pay too little, too late, the IRS charges an underpayment penalty, plus interest on the shortfall. The penalty rate is set each quarter and tracks market interest rates, so it changes over time. It is calculated on the difference between what you should have paid each quarter and what you did pay, for the period it was late. A small shortfall for a short time costs a small amount. A large shortfall for most of the year costs much more. That is why the safe harbor matters: it is the simplest way to be sure the penalty does not apply, even when the estimate is imperfect.

How to set the money aside

The system that works best is boring: a separate account, and a fixed percentage moved the day you are paid. Open a savings account that is only for tax. Every time a client pays you, move a percentage of the payment into it before you spend anything else — 25 to 30 percent is a reasonable starting point for most freelancers, and the estimator will tell you whether your rate should be higher or lower. The money in that account is not yours. It belongs to the tax bill. When a quarterly deadline arrives, the payment is a transfer out of an account that already holds it, not a scramble to find money you have already spent.

Review the percentage twice a year, and keep the habit even in slow months: a small transfer in a slow month is easier than a large one later, and the habit is what survives when the numbers change.