Auto Loan Calculator (with Trade-In & Sales Tax)

What will my monthly car payment be after trade-in, down payment, sales tax and fees?

Combines 2 calculatorsv1.0.0Verified 2026-11-01Runs in your browser

Spec sheet

auto_loan_chain · v1.0.0

Method

sales_tax → loan_payment

01taxable = price − trade-in (most U.S. states tax the difference)
02amount financed = price + sales tax + fees − trade-in − down payment
03payment = amortizing loan payment on the amount financed

Composed from

Limits — read before relying on it

Some states tax the full price regardless of trade-in; enter your state's rule via the tax rate.
Negative equity on the trade-in is not modeled.

Sources

Tax rate supplied by the user for their jurisdictionuser input
Annuity payment formula (present value of an ordinary annuity)formula

Worked example

computed by the same formula

$35k car, $5k trade, $3k down, 7 % tax, 7.5 % for 5 yr

Inputs

Vehicle price: 35000
Trade-in value: 5000
Down payment: 3000
Sales tax rate: 7 %
Dealer, title & registration fees (financed): 800
Loan APR: 7.5 %
Loan term: 5 years

Result

Monthly payment: $599.13
Amount financed: $29,900.00
Sales tax: $2,100.00
Total interest: $6,048.18
Total of loan payments: $35,948.18

1. Sales tax on price after trade-in(Tax) = 2,100
2. Loan payment(Monthly payment) = 599.13

Questions

How is the auto loan calculator calculated?

›

sales_tax → loan_payment. taxable = price − trade-in (most U.S. states tax the difference) · amount financed = price + sales tax + fees − trade-in − down payment · payment = amortizing loan payment on the amount financed

Example: $35k car, $5k trade, $3k down, 7 % tax, 7.5 % for 5 yr?

›

Monthly payment: $599.13; amount financed: $29,900.00.

What does this calculator not cover?

›

Some states tax the full price regardless of trade-in; enter your state's rule via the tax rate. Negative equity on the trade-in is not modeled.

Where do the numbers come from?

›

The formula is versioned (auto_loan_chain v1.0.0) and covered by automated tests.

Is my data stored?

›

No. The calculation runs in your browser and nothing is sent unless you choose to save a shareable link.

Also searched asauto loan calculator · car payment calculator · car loan with trade in · monthly car payment · car loan calculator with tax

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