Owner Operator Quarterly Taxes: How Much to Set Aside and When to Pay
As an owner-operator, no one withholds taxes from your settlement check. That means if you don't set money aside and pay quarterly, the IRS will hit you with an underpayment penalty — plus a tax bill you weren't expecting come April.
Here's exactly what you owe, when you owe it, and how to estimate your quarterly payments without overpaying.
What Self-Employment Tax Is
Company employees split FICA taxes with their employer — 7.65% each, totaling 15.3%. As a self-employed owner-operator, you pay both halves. All 15.3%. On top of your regular federal income tax.
The self-employment tax calculation:
Net profit × 92.35% = SE income base
SE income base × 15.3% = SE tax owed
Example: $60,000 net profit
$60,000 × 0.9235 = $55,410 (SE income base)
$55,410 × 0.153 = $8,478 SE tax
The 92.35% factor accounts for the employer-side deduction you're allowed to take — it slightly reduces your SE tax base. You also get to deduct half of your SE tax from your gross income when calculating regular income tax.
Net profit is gross revenue minus legitimate business expenses: fuel, truck payment, insurance, repairs, permits, ELD fees, factoring fees, and so on. Keep every receipt.
The 4 Quarterly IRS Payment Deadlines
The IRS uses Form 1040-ES for quarterly estimated tax payments. Deadlines for 2026:
| Income Period | Payment Due |
|---|---|
| Jan 1 – Mar 31 | April 15 |
| Apr 1 – May 31 | June 16 |
| Jun 1 – Aug 31 | September 15 |
| Sep 1 – Dec 31 | January 15 (next year) |
Miss a deadline and the IRS charges a penalty based on the underpaid amount — currently around 8% annualized. It adds up fast. Pay at IRS Direct Pay (irs.gov/payments) or by mailing Form 1040-ES with a check.
How to Estimate What You Owe Each Quarter
The safest approach: use the safe harbor rule. Pay 100% of last year's total tax bill divided by 4. Do that and you won't owe an underpayment penalty — even if your income grew.
If last year was your first year as an O/O, estimate based on current net profit:
Step 1 — SE Tax
Net profit × 0.9235 × 0.153 = SE tax
Step 2 — Income Tax
(Net profit − half of SE tax) × your tax bracket rate
Step 3 — Quarterly Payment
(SE tax + income tax) ÷ 4
A common rule of thumb: set aside 25–30% of every net profit dollar into a separate account. When the quarterly deadline hits, the money is already there.
Common Mistakes That Lead to Surprise Tax Bills
- —Calculating tax on gross revenue instead of net profit. After fuel, truck, and operating costs, your taxable profit is often 20–40% of gross — not 100%.
- —Skipping Q1 because you're new. Start-of-year income is still taxable. The April 15 deadline hits fast.
- —Forgetting state estimated taxes. Most states have their own quarterly requirements with their own deadlines.
- —Not tracking deductible expenses. Every business expense reduces your net profit and therefore your tax bill. A $10,000 repair deduction saves you roughly $2,500–$3,500 in taxes.
Bottom Line
Self-employment tax is 15.3% on 92.35% of net profit, plus your regular income tax bracket. Set aside 25–30% of every net profit dollar. Pay quarterly. Use the safe harbor rule if you're unsure.
The IRS doesn't care that you're running loads 70 hours a week. Miss the deadlines and the penalty compounds. Plan ahead and this is completely manageable.
Estimate your quarterly tax payment
PayScale Pro's Quarterly Tax Estimator runs the SE tax math for you — enter your net profit and get a payment estimate in seconds.