Car Down Payment Impact Calculator
See exactly how every extra dollar down changes your payment and total interest.
How much does my down payment change my car payment?
Every dollar down is a dollar you don't finance, so it lowers both the payment and the interest on it. On a $34,000 car at 7.5% APR over 60 months, putting $5,000 down finances $29,000 and costs about $581 a month with roughly $5,866 in interest — about $100 a month less than buying with nothing down.
Your numbers
Monthly payment
$581
Total interest
$5,866
Saved vs $0 down
$100
per month
Insight — A bigger down payment cuts both the payment and the interest you pay on every future month. Around 20% down also helps you avoid being 'underwater' (owing more than the car is worth) early on.
What if Down payment changes?
| Down payment | Monthly payment |
|---|---|
| $0 | $681 |
| $2,500 | $631 |
| $5,000 · now | $581 |
| $10,000 | $481 |
| $15,000 | $381 |
| $20,000 | $281 |
Don't take the first rate you're offered
Get pre-approved by a bank or credit union first, then make the dealer beat it. Our financing tools show what's fair.
Explore financing toolsFree · No sign-up · Independent, source-based math
How this calculator works
The calculator subtracts your down payment from the vehicle price to get the amount financed, then runs that balance through standard fixed-rate amortization at your APR and term to get the monthly payment and total interest. To show the impact of the cash itself, it also amortizes the full price with zero down and reports the difference — how much lower your payment is because of the money you put down. Because interest is charged only on what you borrow, a larger down payment cuts both numbers at once.
Formula
Amount financed = vehicle price − down payment. Monthly payment = financed × monthly rate ÷ (1 − (1 + monthly rate)^−months). Total interest = payment × months − financed. Monthly saving vs $0 down = payment(full price) − payment(financed), where monthly rate = APR ÷ 12.
Worked example
$34,000 price − $5,000 down = $29,000 financed. At 7.5% APR (0.625%/month) over 60 months the payment is about $581, with roughly $5,866 of interest. Financing the whole $34,000 would cost about $681 a month, so the $5,000 down saves about $100 every month.
What affects your result
- →Down payment amount — it comes straight off what you finance
- →Vehicle price, which sets the starting balance
- →APR — a higher rate makes each dollar down save more interest
- →Loan term, which spreads the smaller balance over more or fewer months
- →Reaching roughly 20% down, which helps you avoid owing more than the car is worth early on
What this estimate includes
- ✓Monthly payment at your chosen down payment
- ✓Total interest over the term
- ✓Monthly savings compared with putting nothing down
What it does not include
- ×Sales tax, registration, title and dealer fees
- ×Trade-in value (this tool models cash down only)
- ×Gap insurance and dealer add-ons
- ×It assumes one fixed APR and equal payments for the whole term
Good to know
Clear, practical answers about the down payment impact calculator.
How much should I put down on a car?＋
A common target is 20% down on a new car and 10% on a used car. More down means a lower payment, less interest, and a much lower chance of owing more than the car is worth if you sell early.
🔗 Embed this calculator on your site (free)＋
One line adds the live down payment impact calculatorto your page. It auto-resizes to fit (no scrollbars) and shows a small “Calculator by MotorCrunch” credit — keeping that link is the only condition of use.
<script src="https://themotorcrunch.com/embed.js" data-calc="down-payment-impact-calculator" data-theme="light" async></script>No-script fallback (plain iframe, for CMSes that strip scripts)
<iframe src="https://themotorcrunch.com/embed/down-payment-impact-calculator?theme=light" title="Down Payment Impact Calculator" width="100%" height="760" loading="lazy" style="border:1px solid #e2e8f0;border-radius:12px;max-width:680px;width:100%"></iframe>
<script>window.addEventListener("message",function(e){if(e.data&&e.data.type==="mc-embed-height"){var f=document.querySelector('iframe[src="https://themotorcrunch.com/embed/down-payment-impact-calculator?theme=light"]');if(f)f.style.height=e.data.height+"px";}});</script>All widgets with previews: themotorcrunch.com/widgets