Auto Affordability Calculator
Work backward from a target monthly payment to an estimated maximum vehicle price under the same financing and sales-tax conventions as the Auto Loan calculator. This is a financing estimate — not a statement of what you can responsibly afford or what a lender will approve.
Your results will appear here
Enter your assumptions and calculate to see the estimated result and supporting details.
How this calculator works
Enter maximum monthly payment, down payment, trade-in, APR, term, sales tax rate, and fees.
The calculator finds the maximum loan principal supported by the payment, then solves algebraically for vehicle price.
Formula / methodology
P = M × [(1+r)^N − 1] / [r(1+r)^N] (for r = 0: P = M × N) V = (P + Down − Fees) / (1 + t) + Trade-in (when V ≥ Trade-in; otherwise tax = 0)
- Uses the shared reverse-payment helper (principalFromPayment).
- Vehicle price derivation matches the Auto Loan tax convention in reverse.
- Cross-check: feeding the resulting price into Auto Loan should reproduce approximately the same monthly payment.
Worked example
A $500 monthly payment at 6% APR for 60 months supports about $25,862.78 of financing.
With $5,000 down, $5,000 trade-in, 6% tax, and $500 fees, the estimated maximum vehicle price is about $33,644.13.
Important assumptions
- Payment-based financing estimate only — not budgeting advice or lender approval.
- Same sales-tax convention as Auto Loan.
- Does not model credit score, income, or insurance requirements.
Common questions
No. It is the estimated vehicle price supported by the payment assumptions — not a judgment of responsible affordability or approval odds.
For the same APR, term, tax, fees, down payment, and trade-in, Auto Loan should reproduce the target payment within cents-level rounding.
High fees reduce the vehicle price supported by a given loan amount. If the result is not positive, the calculator reports a limitation.