Car + OT Withholding Calculator
For OT workers with auto loans.
The short answer: At the scenario numbers pre-loaded below, the OBBBA deductions total $8,725, worth about $1,047 in federal income tax at a 12% marginal rate ($40 per biweekly paycheck) — that's the gap your W-4 can capture during the year.
Total OBBBA above-the-line deductions: $8,725
Extra tax you are on track to over-withhold: $1,047
≈ $40 per biweekly paycheck
File a revised W-4 (Step 4a "other income" negative adjustment or dependents/credits line) to bring this money home in each paycheck instead of waiting for a refund.
⚠️ This calculator provides estimates for informational and educational purposes only. It is not tax advice. Results are based on the One Big Beautiful Bill Act (OBBBA) and IRS Schedule 1-A. Consult a qualified tax professional for your specific situation.
Withholding vs. What You Actually Owe
Two deductions, one 4(b) entry: premium + interest.
- • OT premium deduction (cap $12,500/$25,000) + interest (cap $10,000)
- • Same MAGI phase-out governs both
- • The calculator combines them
Worked Example
A worker with 350 OT hours and a $4k-interest loan.
- • Total OBBBA deductions: $8,725
- • Federal income tax savings: $1,047 at the 12% marginal rate
- • Per biweekly paycheck: $40 — capture it via a W-4 4(b) adjustment instead of waiting for refund season
Keep Reading
Frequently Asked Questions
Can I put both deductions on one W-4 line?
Yes — 4(b) takes the combined annual total of all deductions.
Do the caps interact?
No — separate caps, separately applied.