Knowing that you owe quarterly estimated taxes is one thing. Figuring out the actual dollar amount to send the IRS four times a year is a different challenge entirely, and it’s the part that trips up most new freelancers. The good news is that once you understand the moving pieces, the math itself isn’t complicated. Here’s a complete walkthrough of how to arrive at a number you can actually trust.
The Two Taxes You’re Estimating
Every quarterly payment you make is really covering two separate tax obligations at once:
- Self-employment tax, which funds Social Security and Medicare and is calculated at 15.3% on 92.35% of your net profit
- Federal income tax, calculated on your total taxable income using the regular tax brackets
Many freelancers only budget for one of these and get blindsided by the other. Your quarterly estimate needs to account for both, plus any state income tax you owe if you live in a state that collects it.
Step 1: Project Your Net Self-Employment Profit for the Year
Start by estimating your total business income for the year, then subtract your expected business expenses. If you’re early in the year and don’t have a full picture yet, use your prior year’s numbers as a baseline and adjust for any known changes, like a new client, a rate increase, or a slower season you’re expecting.
For freelancers with irregular income, it often works better to estimate quarter by quarter rather than trying to project the whole year at once, and to adjust each subsequent payment based on how the year is actually unfolding.
Example
Let’s say you’re a freelance copywriter who expects to earn $90,000 in gross revenue this year, with $10,000 in deductible business expenses (software, a home office deduction, contractor help, and so on). That leaves you with a projected net profit of $80,000.
Step 2: Calculate Your Estimated Self-Employment Tax
Using the formula covered in our self-employment tax guide, multiply your net profit by 92.35%, then apply the 15.3% rate:
$80,000 × 92.35% = $73,880
$73,880 × 15.3% = $11,303.64
So in this example, you’d owe roughly $11,304 in self-employment tax for the year, assuming your income stays well under the annual Social Security wage base.
Step 3: Calculate Your Estimated Federal Income Tax
This is the part most freelancers get wrong, because they apply their tax bracket to their entire net profit instead of their actual taxable income. Before you apply the tax brackets, you need to:
- Subtract half of your self-employment tax (an above-the-line deduction)
- Subtract the standard deduction, or your itemized deductions if those are higher
- Subtract any other above-the-line deductions you qualify for, such as a SEP IRA or Solo 401(k) contribution or the self-employed health insurance deduction
Continuing the Example
Half of your self-employment tax ($11,304 ÷ 2) is $5,652. Subtracting that from your $80,000 net profit brings you to $74,348. If you’re a single filer taking the 2026 standard deduction of $16,100, your taxable income drops to $58,248.
Using the 2026 federal tax brackets for single filers, that amount is taxed progressively: 10% on the first portion, 12% on the next, and 22% on the remainder above roughly $50,000. Running the math through all three brackets lands you at approximately $7,900 in federal income tax for the year, though your exact number will shift slightly depending on other deductions or credits you qualify for.
Step 4: Add State Income Tax, If Applicable
If you live in a state with income tax, you’ll need to estimate that separately, since state tax isn’t part of the federal self-employment tax or income tax calculation. Rates and rules vary significantly by state, so check your state’s Department of Revenue for its specific brackets and estimated payment requirements. If you live in a state with no income tax, such as Texas or Florida, you can skip this step entirely.
Step 5: Add It All Up and Divide by Four
Combining the numbers from our example:
- Self-employment tax: $11,304
- Federal income tax: $7,900
- Total estimated federal tax liability: $19,204
Divide that by four to get a quarterly payment of roughly $4,801. If you also owe state tax, add your estimated state liability before dividing.
An Easier Shortcut: The Safe Harbor Method
If projecting your income precisely feels overwhelming, especially with unpredictable freelance work, there’s a simpler and very common approach: base your payments on your prior year’s total tax liability instead of trying to predict the current year from scratch.
The IRS won’t charge you an underpayment penalty as long as you pay, through withholding and estimated payments combined, at least:
- 100% of last year’s total tax liability, or 110% if your prior-year adjusted gross income was over $150,000
This «safe harbor» approach means you can simply take last year’s total tax bill, divide it by four, and pay that amount each quarter, regardless of how this year actually turns out. If you end up owing more, you’ll settle the difference when you file, without any penalty for underpayment during the year. This is often the least stressful method for freelancers whose income varies significantly from month to month.
Adjusting Mid-Year If Your Income Changes
Your quarterly payments don’t have to stay identical all year. If you land a major new client in Q3 or lose a recurring contract, it’s worth revisiting your estimate rather than mechanically sticking with your original number. Freelancers with seasonal or lumpy income sometimes use the annualized income installment method (Form 2210, Schedule AI), which lets you calculate each quarter’s required payment based on income actually earned during that specific period, rather than assuming an even split across the year. This can meaningfully reduce or eliminate penalties if most of your income arrives later in the year.
Tools That Make This Easier
You don’t have to run this math by hand every quarter. A few practical options:
- IRS Form 1040-ES worksheet — the official method, useful if you want full control over every input
- Accounting software with built-in tax estimates (QuickBooks Self-Employed, FreshBooks) — automatically tracks income and expenses and estimates your quarterly payment as you go
- A simple spreadsheet — tracking gross income, expenses, and a running tax-liability estimate updated monthly
- A CPA or Enrolled Agent — especially valuable in your first year or two of self-employment, or if your income is complex or highly variable
A Practical Habit: Set Aside the Percentage as You Get Paid
Rather than waiting until the deadline approaches to figure out what you owe, many freelancers set aside a fixed percentage of every payment the moment it arrives, moving it into a separate savings account earmarked only for taxes. A common starting point is 25-30% of gross income for combined federal income tax and self-employment tax, adjusted up or down based on your specific bracket and state. This turns quarterly taxes from a stressful scramble into a routine transfer you’ve already prepared for.
Quick Recap
- Your quarterly payment needs to cover both self-employment tax (15.3% on 92.35% of net profit) and federal income tax on your actual taxable income, plus state tax if applicable.
- Remember to subtract half your self-employment tax, your standard or itemized deductions, and any other above-the-line deductions before applying the income tax brackets.
- The safe harbor method, paying based on 100% (or 110% for higher earners) of last year’s tax bill, is often simpler and just as effective as projecting the current year from scratch.
- Adjust your payments mid-year if your income changes significantly, using the annualized income method if your earnings are seasonal.
- Setting aside a percentage of every payment as it arrives makes each quarterly deadline far less stressful.
Frequently Asked Questions
What if I estimate too high and overpay during the year? You’ll receive the excess back as a refund when you file your annual return, similar to overpaid withholding from a W-2 job.
Can I just pay 25% of my income each quarter and call it done? That’s a reasonable starting estimate for many freelancers in the 22-24% federal tax bracket, but it doesn’t account for your specific deductions, filing status, or state tax situation. It works better as a rough guideline than a precise calculation.
Do I need to recalculate every single quarter? Not necessarily, especially if you’re using the safe harbor method. But if your income changes significantly partway through the year, revisiting your estimate helps you avoid a large balance due (or a large overpayment) when you file.
What happens if my income is much lower than I projected? You can reduce your remaining quarterly payments for the rest of the year to reflect the lower income. You’re not locked into your original projection.
This article is for general informational purposes and reflects federal tax rates, brackets, and thresholds for the 2026 tax year. State tax rules vary and are not covered here. Always confirm current figures with the IRS or a qualified tax professional (CPA or Enrolled Agent) before making payments.