Debt vs. Invest Calculator
Should you pay off debt or invest? Find out after taxes.
7 followers
Should you pay off debt or invest? Find out after taxes.
7 followers
Most calculators compare debt rates to investment returns before taxes. That's often the wrong answer. A 5% HYSA vs. a 4% car loan looks like a +1% win. After taxes, it can become **-0.40%**—meaning paying off the loan wins. This calculator uses 2026 U.S. tax rules, including federal brackets, NIIT, HYSA/T-Bills/stocks/IRAs, car & student loan deductions, mortgage rules, state tax treatment, and shareable links. Free. Open source. No signup. Feedback welcome.
would love to see a way to model multiple debts side by side, so i can see whether paying extra on the car loan vs. the student loan vs. the mortgage gives the biggest after-tax benefit given the specific deduction rules for each.
@erkansulumutlu Great suggestion Erkan — multi-debt comparison is on the roadmap.
The tricky part is the phase-out interactions when you have
both a student loan and mortgage simultaneously. Will build it.