Know your deal
before you sign.
The dealership runs these numbers every day. Now you can too — free, in under a minute. Enter what they gave you and find out if it’s actually a good deal.
Loan Calculator
Payment · interest · rate health
Lease Calculator
Monthly cost · deal rating
Affordability
Budget range · DTI check
1-2%
Typical dealer rate markup
$1,400
Extra interest from dealer financing
19%
Avg. new car depreciation, year one
The Tools
The numbers they’re not showing you.
Every calculator here was built around a specific way dealers extract money from buyers who don’t know the real math.
Loan Calculator
Enter price, APR, term, and fees. Get your real monthly payment, total interest, and a plain verdict on whether your rate is competitive.
- Monthly payment
- Total interest
- Out-the-door cost
- Rate health rating
Lease Calculator
Put in your money factor, residual, and cap cost. Get the full breakdown — including the APR equivalent your dealer almost certainly never mentioned.
- Monthly payment
- Due at signing
- Effective APR
- Deal rating
Affordability Calculator
Set your ceiling before you shop. Anchor your budget to income and real obligations — not to what the finance manager says he can make work.
- Safe payment range
- Vehicle price range
- Debt-to-income ratio
- Budget assessment
Depreciation Calculator
What your car will actually be worth in 1, 3, and 5 years.
Fee Decoder
Which line items are real, which are negotiable, which to decline.
Lease vs. Loan
Run both options on the same vehicle, side by side.
Done-for-You Negotiation
Hate the back-and-forth? We know someone who does it for you.
The Hidden Math
What the monthly payment is hiding.
Three things dealers know that most buyers don’t — and exactly how to check them.
1–2%
The rate markup you never see
Dealers receive a buy rate from the lender, then quote you higher and pocket the difference. On a $35,000 loan over 60 months, a 2% markup is roughly $2,100 out of your pocket. It's legal, it's standard practice, and it's never mentioned.
Check your rate$3,800
The cost of saying yes to 72 months
A 72-month loan at 7% vs. 48 months at 6.5% on the same car. The longer term drops your payment — and costs you $3,800 more in interest over the life of the loan. Dealers prefer you focus on the monthly number. We show you the full one.
Run the numbers×2,400
The lease number dealers skip
The money factor is how interest hides in a lease. Multiply it by 2,400 to get the APR equivalent. A money factor of 0.0028 is 6.7% APR. If the manufacturer's published rate is 0.0015, you're paying 3% extra — and it doesn't appear anywhere on the quote sheet.
Decode a leaseWhy This Exists
Car deals have more levers than most buyers realize.
Price, rate, term, fees, trade-in — each adjusted independently by someone who does this every single day. This site gives you the same math they’re running.
About this siteThe monthly payment is the wrong number to focus on.
Dealers negotiate from payment, not price. They can hit any number you name by stretching the term, burying fees, or adjusting the rate — while quietly adding thousands to what you actually pay.
Most buyers overpay and never find out.
Not because they were careless. Because the numbers are designed to be difficult to check quickly. A five-minute review before you sign changes that.
Lease math is intentionally opaque.
Money factors, residuals, adjusted cap costs — none of it is accidental. Dealers benefit from complexity. We run the same math and give you a straight answer: good deal, fair deal, or walk.
We built this because we worked the other side.
The tools here reflect how deals are actually structured inside a finance office — not how they're presented to buyers. That's the difference between a calculator and a real answer.
Real Results
Buyers who ran the numbers first.
These aren’t edge cases. Dealer markups, fee padding, and inflated money factors happen on most deals — to buyers who don’t check.
I ran the numbers the night before and walked in knowing my rate was 2% over market. Showed the dealer my pre-approval and they matched it in five minutes. Saved about $1,800.
Ryan M.
2024 Honda Accord — Columbus, OH
The lease calculator showed me the dealer had marked up the money factor by 0.0012 over the published rate. I asked them to match it and they did without any pushback.
Sarah K.
2025 BMW X3 — Austin, TX
I used the fee decoder and realized I was about to pay $800 in junk fees I had no idea were optional. Declined all of them. No questions asked.
Marcus T.
2023 Toyota RAV4 — Atlanta, GA
Lease or buy — which is actually cheaper?
It depends entirely on the specific deal in front of you. Here’s what each path actually means financially.
Financing (Loan)
Pros
- You own the car outright when paid off
- No mileage limits or wear-and-tear fees
- Build equity you can use toward your next vehicle
- Freedom to modify, sell, or keep as long as you want
Cons
- Higher monthly payments than a comparable lease
- You absorb the full depreciation of the vehicle
- Maintenance costs rise as the car ages
Leasing
Pros
- Lower monthly payments for the same vehicle
- Always driving a new car every 2–3 years
- Often covered under factory warranty the whole term
- No hassle selling or trading in at the end
Cons
- You own nothing at the end — no equity built
- Mileage caps (usually 10k–15k/year) with fees for overages
- Wear-and-tear charges at lease return
- Early termination is expensive
Ask yourself these questions
Do you drive more than 15,000 miles/year?
Lean toward buying — mileage overages on leases add up fast.
Do you want to own the car long-term?
Buy. Leasing means starting payments again every 2–3 years forever.
Is cash flow tight right now?
Leasing offers lower monthly payments for the same vehicle.
Do you always want a new car under warranty?
Leasing makes that automatic — and cheap.
Run both numbers on your actual deal to see which comes out ahead.
The Dealer’s Playbook — Now Yours
The one-page reference used by buyers who know what they’re walking into. Covers financing, fees, leases, and negotiation — the stuff that doesn’t come up until you’re already at the table.
- The exact number dealers mark up on financing (and by how much)
- Which fees are real, which are negotiable, and which are pure markup
- How to read a lease deal in under 2 minutes
- The script for asking a dealer to beat your pre-approved rate
FAQ
Common questions
Straight answers before you calculate.
More on car financing in our guides.
Read the blog