About this car loan interest calculator

This is a free, browser-based estimator for the 2026 car loan interest deduction created by the One Big Beautiful Bill Act. Enter the interest you paid, your filing status, your modified adjusted gross income, and whether the vehicle qualifies, and it returns the deduction cap that applies after the income phaseout, the deduction you can claim, and an estimate of the federal tax it would save.

Where the numbers come from

The rules encoded here are the statutory figures for tax years 2025 through 2028: a $10,000 cap, a $200-per-$1,000 phaseout above $100,000 (single) or $200,000 (joint), a 14,000-pound GVWR ceiling, the US final assembly and VIN requirements, and Form 1098-VLI reporting at $600 or more of interest. These were checked against the IRS overview, the IRS transition relief notice, and the Federal Register final rule during the build, and are stored as a dated constants module.

What it does not do

It does not confirm your specific vehicle's eligibility, it does not file your return, it does not see the rest of your tax picture, and it does not store anything you type. The tax-saved line is a first-order estimate based on the single marginal rate you choose. Treat the output as a planning estimate, not tax advice.

Related tools

Estimate the No Tax on Overtime deduction and the No Tax on Tips deduction, or read the overview on the 2026 Tax Rules hub.