Who built this and why
My name is Ryan Doyle, and I spent nine years working as a finance manager at auto dealerships in the midwest.
My job was to sell loans.
Not cars — loans. The car sale was the sales team’s job. My job started after you shook hands on the vehicle price. I sat across a desk, pulled your credit, and presented you with a monthly payment. That payment was built on a rate the dealership marked up above what the lender actually required. The difference went to the dealer. That was standard practice, and most buyers had no idea it was happening.
I was good at my job. That part bothers me a little now.
After leaving the industry, I kept thinking about how many people were sitting in loans that were two or three points higher than they needed to be — not because of their credit, not because of the market, but because nobody told them they could do better. A refinance is not complicated. The math is straightforward. But most people never run the numbers because nobody hands them the tool to do it.
That is what this site is.
What I actually know
Nine years in dealership finance means I have seen a lot of loan files. I know how lenders tier borrowers. I know what the rate sheet looks like before the markup. I know which vehicles get flagged during underwriting and why a 2017 truck with 95,000 miles is treated differently than a 2020 sedan with 40,000.
I also made mistakes when I was starting out — approved loans I should have pushed back on, extended terms on nearly-paid vehicles, and once convinced a customer to roll negative equity into a new loan because the math “worked on paper.” It did not work for him in the long run. That one stayed with me.
After leaving dealerships I spent three years doing consumer credit consulting, mostly helping people figure out whether their existing auto loans were worth refinancing and walking them through the process of finding a better rate. Most of the time the answer was yes, and most of the time it took about two weeks and one phone call to a credit union.
I built this calculator because I got tired of explaining the same break-even math on a napkin.
How this site works
Every article on this site is written from the finance office side of the desk. I know what lenders are looking for because I used to submit files to them. The rate benchmarks I use come from CFPB data, NCUA credit union rate surveys, and Experian’s quarterly automotive finance reports — not guesses.
The calculator itself uses standard amortization formulas. It is the same math lenders use. Nothing fancy, nothing proprietary. Just the actual numbers, which are usually enough to tell you whether a refinance makes sense within about five minutes.
One thing I want to be clear about: this site does not give financial advice, and I am not your financial advisor. What I can do is show you the math clearly enough that you can make the decision yourself. That is the whole point.
Editorial standards
Every article goes through three checks before it goes live:
First, the math. Any rate example or payment calculation gets verified against standard amortization before publishing. I have seen too many finance articles with numbers that simply do not add up.
Second, the lender benchmarks. APR ranges and credit tier thresholds get checked against current data before I publish them. Rates move. What was accurate six months ago may not be accurate today.
Third, the plain language check. If I cannot explain something clearly enough that a first-time car buyer can act on it, I rewrite it. The dealership version of this information was deliberately confusing. This site is not.
Where to find me
I share rate observations and refinance timing notes on X at refinancing_car and answer auto loan questions on Quora. Longer analysis goes on Medium.
If you have a question about your specific loan situation, the Contact page is the best place to reach me. I read everything, though I cannot always reply individually.
A note on the name
I write under Ryan Doyle rather than my full name for the same reason a lot of people in the lending industry do: the auto finance world is smaller than it looks, and opinions about dealer rate markup are not universally popular among former colleagues. The analysis on this site speaks for itself.
Auto Loan Refinance Calculator is an independent site. We are not a lender, broker, or financial institution. Calculator outputs are estimates for educational purposes only and do not constitute financial advice.