Tax Refund Estimator: Refund or Owe?

It's November. You've been at your job all year, your last pay stub shows $18,400 in federal withholding, and you have no idea if that's too much, too little, or about right. You could file in April and find out—or you could estimate now and still have time to fix it.

This tool is for anyone who wants to know where they stand before tax season. Maybe you're curious whether you'll get a refund or owe money. Maybe you got a $4,200 refund last year and realized that was $350/month you could have had in your paycheck. Maybe you started a side gig and you're worried about a surprise bill.

Whatever your situation, this estimator shows you the gap between what you've paid and what you'll likely owe—so you can plan instead of guess.

• Your withholding settings: The W-4 you filled out tells your employer how much to withhold. Claim zero allowances and you'll over-withhold (big refund). Claim too many and you'll under-withhold (balance due). Most people set it once and forget it.
• Non-wage income: Side gigs, dividends, rental income, stock sales—none of these have automatic withholding. Every dollar of non-wage income pushes you toward owing unless you adjust your W-4 or make estimated payments.
• Pre-tax deductions: Your 401(k) contribution, HSA, and health insurance premiums reduce taxable income before it even hits your paycheck. These lower your actual tax liability without you doing anything extra.
• Credits you qualify for: Child Tax Credit ($2,000 per kid), education credits, energy credits—these directly reduce tax owed. Refundable credits like EITC can push you into refund territory even if you owe zero tax.
• Filing status: Single vs. married filing jointly vs. head of household changes your standard deduction and bracket thresholds. The wrong status on your W-4 means withholding won't match reality.

Example 1: Sarah Over-Withholds Without Realizing It

Sarah earns $72,000 as a marketing manager in Ohio. She filled out her W-4 as single with no adjustments when she started three years ago. She contributes $4,320 to her 401(k) and has health insurance through work.

Sarah's been getting a ~$2,300 refund every year and thought she was doing great. But that's $192/month she gave the government interest-free. She could adjust her W-4 to reduce withholding and have that cash in her paycheck instead.

Example 2: Marcus Gets Blindsided by Side Income

Marcus works as an accountant making $95,000. He also does freelance bookkeeping on the side, earning $18,000 in 1099 income. His W-2 job withholds correctly for his salary—but nothing is withheld from the freelance work.

Marcus owes almost $6,000 plus potential underpayment penalties. Had he run this estimate in October, he could have made a Q4 estimated payment or increased withholding from his W-2 to cover the gap.

• Celebrating a big refund: A $4,000 refund isn't a bonus—it's $333/month you overpaid all year. The IRS doesn't pay you interest on that loan. Target a refund between $0 and $500 instead.
• Ignoring side income: Freelance, gig, rental, or investment income has no automatic withholding. Every dollar goes unreported to your W-2 employer. If you don't adjust, you'll owe.
• Forgetting life changes: Got married? Had a baby? Bought a house? Your withholding doesn't automatically update. A mid-year marriage can throw off your entire year's calculation.
• Confusing federal and state: You might get a federal refund but owe state taxes. Or vice versa. Run both calculations—they're completely separate.
• Missing the $1,000 threshold: If you owe more than $1,000 when you file and didn't pay enough during the year, you'll face underpayment penalties. Catching this in November gives you time to make a payment.

We take your income, subtract deductions to get taxable income, apply federal tax brackets, subtract credits, then compare that liability to what you've paid.

2025 standard deductions: $15,000 (single), $30,000 (married filing jointly), $22,500 (head of household).

What we include: Federal income tax using 2025 brackets, standard deduction, credits you enter, and all payments (withholding plus estimated).

What we don't include: State taxes (calculate separately), AMT, specific credit phase-outs, or special income types (qualified dividends, long-term capital gains at preferential rates). This is a planning estimate—not a substitute for your actual tax return.