Calculator

Car Buying

Find the vehicle price that fits the 20/3/8 rule after your trade, payoff, and cash down.

Your information stays in this browser. Last reviewed July 17, 2026
20% Put down Cash plus positive trade equity
3 Years or less Maximum 36 month loan term
8% Of gross income All household car payments combined
01

Income and payment room

$
Before taxes. Use household income only if buying jointly.
$ /mo
Include another household vehicle that will not be traded.
02

Your current car

Current trade value
$
mi
Rough private-party estimate$0
Conservative trade estimate used$0

This broad depreciation model cannot see the make, trim, condition, accident history, or local market. Use it only for planning, then replace it with real dealer or pricing-guide quotes.

$
Get the payoff from your lender. It can differ from the displayed balance.
$ /mo
mo
03

The next deal

$
Do not count emergency savings you need to keep.
%
36 months
20 / 3 / 8 analysis

Your buying limit

Current vehicle not listed
Trade position $0
Maximum responsible vehicle price
$0
Before sales tax, registration, dealer fees, warranties, and add-ons.
New payment
$0
0.0% of gross
Amount financed
$0
36 mo at 0.0%
Available down
$0
cash plus trade equity
Loan interest
$0
if held for the full term
RESULT
See the full calculation

Trade and down payment

Current vehicle value$0
Less loan payoff$0
Trade equity$0
Plus cash down$0
Total available down payment$0

Payment and price limits

Gross monthly income$0
8% total car payment cap$0
Other continuing car payments$0
Available new-car payment$0
Maximum loan from payment rule$0
Price cap from payment rule$0
Price cap from 20% down rule$0
Binding limit20% down

The optional vehicle estimate assumes broad average depreciation, 12,000 miles per year, and a 10% dealer discount from estimated private-party value. It is a planning estimate, not an appraisal. The 20/3/8 framework is a conservative guideline, not a lender approval or a complete household budget.

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Educational content only. Not investment, tax, or legal advice. Nothing on this site creates an advisory relationship. Consult a licensed professional before making decisions about your money.
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