Dealer Financing vs. Credit Union Financing Calculator
Use this calculator to help you determine whether you should take advantage of low interest dealer financing or credit union financing combined with a manufacturer rebate.
How the dealer financing vs. credit union financing calculator works
It amortizes the same loan at the dealer's rate and at a credit union's rate, then compares the monthly payment and total interest so you can see exactly what convenience at the dealer costs.
Worked example: with amount financed of $30,000, loan term (years) of 5 and dealer interest rate of 8.50%, the dealer financing vs credit union financing calculator shows saved with the credit union of $1,711.
- Dealer payment
- $615.50
- Credit union payment
- $586.98
- Dealer total interest
- $6,930
- Credit union interest
- $5,219
The formula
Each lender: Payment = amount × r ÷ (1 − (1 + r)⁻ⁿ). The saving is the difference in total interest between the two rates.
Results are estimates for educational purposes and are not financial advice. Confirm exact figures with your lender, plan administrator or advisor.
Questions about the dealer financing vs. credit union financing calculator
Is dealer financing more expensive?
Often, because the dealer can mark up the rate. A credit union or bank pre-approval frequently beats it — this calculator shows the dollar difference on your loan.
Should I get pre-approved before visiting the dealer?
Yes. A pre-approval gives you a rate to beat and negotiating leverage, so you can accept dealer financing only if it genuinely undercuts your credit union.
Can I refinance later if I take dealer financing?
Usually yes — if you later qualify for a lower rate, refinancing the auto loan can recover much of the difference. Compare with our auto refinance calculator.
Is the Dealer Financing vs. Credit Union Financing Calculator free to use?
Yes. Every calculator on FinCalculators is completely free, with no sign-up, login or paywall. You can run as many scenarios as you like.