Washington Auto Loan Calculator (with Washington Sales Tax & Fees)

The number to know first is that Washington's state rate on a car is not 6.5%. It is 7.0%, and as of 2026 it is not 6.8% either.

Washington charges the 6.5% state retail sales tax under RCW 82.08.020(1), then adds a separate motor vehicle sales and lease tax under RCW 82.08.020(3) that applies only to vehicles. That additional tax rose from 0.3% to 0.5% effective 1 January 2026. Any rate table, dealer worksheet, or online estimate still showing 6.8% for a Washington car is running on pre-2026 data and understates the tax by 0.2 percentage points, which is $70 on a $35,000 purchase.

The second thing to know is that the state figure is the smaller half of the bill in most of the state. Washington local sales taxes apply to vehicles at the same rate as everything else, with no reduced automotive rate, and combined local rates in the Puget Sound region run above 3%. A buyer facing a 3.5% local rate pays 10.5% all in, which turns $2,464 of tax into $3,696.

Because local rates vary by street address and change quarterly, this calculator takes the local rate as an input rather than shipping a rate table. Look yours up on the Department of Revenue Tax Rate Lookup tool using the address where the vehicle will be delivered or registered, then enter it.

The APR columns below are national averages, not Washington figures. No primary source publishes average auto loan APR by state: Experian's report has no geographic cut, the CFPB publishes state origination volume but no rates, and the New York Fed publishes state delinquency only. The payment column is the part that is specific to Washington, because it runs this calculator's own Washington tax and fee rules at each tier's rate.

Payment assumptions: $35,000 vehicle price, $0 trade-in, $5,000 cash down, $200 dealer documentation fee, 60-month term, new-vehicle APR applied to the Washington delivered price including tax and statutory fees. At the 6.39% overall new-car average the same purchase costs $639.11 a month.

The score bands are VantageScore 4.0, not FICO. The same borrower can land in a different tier under each model, so a FICO score pulled from a card issuer will not always match the band here. Source: Experian, State of the Automotive Finance Market, Q1 2026, slide 45.

Each row changes one input and leaves the rest at the baseline below. The dollar effects are this calculator's own output for Washington, not a rule of thumb.

Baseline: $35,000 vehicle price, $0 trade-in, $5,000 cash down, $200 documentation fee, 60 months at 7.25% APR, giving a $652.36 payment and $6,391.58 of total interest.

Washington charges 7% on a vehicle, half a point above its 6.5% general sales tax rate, then adds the local rate for the sourcing address. Five steps.

1. Net taxable selling price. RCW 82.08.010(1) defines selling price as the consideration paid "except separately stated trade-in property of like kind." A vehicle traded for a vehicle qualifies, with no dollar cap. The dealer's documentary service fee is part of the selling price and is taxed.

The trade-in allowance cannot exceed the price of the car you are buying, so an oversized trade leaves the doc fee taxable rather than driving the base below zero.

2. Sales tax. The state figure is fixed; the local rate is whatever applies at the sourcing address.

3. Registration. A fixed $86, being the $30 vehicle license fee, a $35 weight fee for a passenger car at or under 4,000 pounds, and roughly $21 of filing and service fees. Registration is not part of the taxable selling price.

4. Amount financed. The trade-in works twice. It lowered the tax base in step one, and it also reduces the balance you borrow.

5. Amortization. The financed amount amortizes as a fixed-rate installment loan:

where $P$ is the financed amount, $i$ is the monthly rate (APR ÷ 12), and $n$ is the term in months.

Every published combined rate for Seattle, Bellevue, Tacoma, Spokane, and Vancouver that we could check came from secondary aggregators rather than the Department of Revenue rate lookup, and two of those sources disagree with each other on Seattle by 0.2 points. Rather than print a number that might be wrong on the one page where a wrong number costs you money, this calculator asks you for the rate.

What can be said with confidence about the geography:

Washington sources vehicle sales tax to destination. For a dealer-delivered vehicle the rate follows the delivery location, and for a vehicle the buyer registers it follows the buyer's address. Buying in a low-rate county does not get you a low-rate bill if you garage the car somewhere else.

Sound Transit's Regional Transit Authority district, covering parts of King, Pierce, and Snohomish counties, charges materially more than the rest of the state on a car, but the extra charge is not a sales tax. It is a 1.1% annual motor vehicle excise tax on depreciated MSRP, billed at registration and again at every renewal. On a car with a $35,000 depreciated value that is roughly $385 in the first year, recurring. If you live inside the RTA boundary, budget for it separately from anything this calculator shows, and expect your total first-year cost of ownership to exceed a comparable purchase outside the district by several hundred dollars.

Washington's 7.0% is itself two layers: the 6.5% retail sales tax plus the 0.3% motor vehicle tax added by RCW 82.08.020(3). Local rates then push the real figure past 10% in parts of the Puget Sound region, so the run below is a state-only reference point.

• Vehicle price: $35,000
• Trade-in allowance: $0
• Cash down: $5,000
• Documentary service fee: $200
• Local rate: 0% (state figure only)
• Term: 60 months at 7.25% APR

Step 1 -- The taxable selling price. Selling price including the capped service fee, less separately stated like-kind trade-in property: $35,000 + $200 - $0 = $35,200.00

Step 2 -- Vehicle sales tax at 7.0%. $35,200.00 x 7.0% = $2,464.00

Step 3 -- Registration, outside the base. $86.00

Step 4 -- Total delivered price. $35,000 + $200.00 + $2,464.00 + $86.00 = $37,750.00

Step 5 -- Amount financed. $37,750.00 - $0 trade-in - $5,000 cash down = $32,750.00

Step 6 -- The monthly payment. $32,750.00 at 7.25% over 60 months = $652.36

Step 7 -- Month 1. $32,750.00 x (7.25% / 12) = $197.86 interest, $454.50 principal, balance $32,295.50

Step 8 -- Month 2. $32,295.50 x (7.25% / 12) = $195.12 interest, $457.24 principal, balance $31,838.26. Cumulative interest: $392.98

Step 9 -- The accumulation. Interest through month 12 is $2,189.46, balance $27,111.14. Over the full term, $6,391.58

Add a $10,000 like-kind trade-in and nothing else changes. The taxable selling price drops to $25,200, tax falls to $1,764.00, and the payment drops to $439.22. The trade-in saved $700 in tax at the state figure alone. At a 10.5% combined rate the same trade-in would save $1,050.

Now put the same purchase somewhere with a 3.5% local rate. Tax rises to $3,696.00, the financed balance to $33,982.00, and the payment to $676.90. That is $24.54 a month, or $1,472 over the life of the loan, purely from where the car is registered.

• The RTA motor vehicle excise tax. The 1.1% annual Sound Transit MVET on depreciated MSRP is a recurring registration charge inside parts of King, Pierce, and Snohomish counties, not a purchase tax, so it is not added to the delivered price here.
• Title fees. Washington's title application charge and its filing and service surcharges were not confirmed against a Department of Licensing schedule, so no title amount is included in the total at all. Expect to add a modest amount at the counter rather than treat this figure as complete.
• The 2026 vehicle luxury tax. Washington enacted new motor vehicle taxes beginning in 2026 that law firm commentary describes as applying above a price threshold. The threshold and rate were not confirmed against statute, so nothing is modeled. If you are buying an expensive car, ask the dealer directly.
• Weight-based registration above a passenger car. The $35 weight fee assumes 4,000 pounds or less. Heavier vehicles pay more, reaching $65 at 6,000 pounds, and many cities add Transportation Benefit District fees.
• Electric vehicle registration surcharges, which Washington charges annually in addition to the fees above.
• GAP insurance, service contracts, and aftermarket add-ons, unless you fold them into the vehicle price yourself.

• Using 6.8% for a 2026 purchase. The additional motor vehicle tax went from 0.3% to 0.5% on 1 January 2026. On a $35,200 base the stale figure understates tax by $70.40.
• Using 6.5% and forgetting the vehicle add-on entirely. That is a $176 error on the same purchase, and it compounds when you then apply a local rate to the wrong subtotal.
• Assuming your local rate follows the dealership. Sourcing is by destination. A Spokane resident buying in Seattle pays Spokane's rate, and a Seattle resident buying in Vancouver pays Seattle's.
• Treating the RTA charge as part of the purchase price. It is annual. Rolling it into the loan calculation once understates the real cost of living inside the district and overstates the amount you need to finance.
• Selling privately instead of trading in without doing the arithmetic. The trade-in exclusion is worth the allowance times your full combined rate, which is $700 to $1,050 on a $10,000 car. A private sale has to beat the dealer's offer by more than that to win.
• Judging the loan by the payment. Stretching this $32,750 balance from 60 to 72 months drops the payment to $562.29 and raises total finance charges from $6,391.58 to $7,735.27.

• Consumer Financial Protection Bureau, Truth in Lending Act (Regulation Z, 12 CFR § 1026.22) disclosure requirements for installment credit. ecfr.gov/current/title-12/chapter-X/part-1026
• Washington State Department of Revenue, the official state tax authority for Washington rates, rules and forms. dor.wa.gov

Also consulted: RCW 82.08.020(1) (6.5% state retail sales tax) and RCW 82.08.020(3) (additional motor vehicle sales and lease tax, 0.5% from 1 January 2026); Washington Department of Revenue, motor vehicle sales and use tax guidance; RCW 82.08.010(1) (selling price definition and like-kind trade-in exclusion) and WAC 458-20-247 (trade-in mechanics); RCW 46.70.180(4) (documentary service fee cap); Washington Department of Licensing, Regional Transit Authority (RTA) tax guidance and passenger vehicle fee schedule; Experian, State of the Automotive Finance Market, Q1 2026, slide 45 (average new and used auto loan APR by VantageScore 4.0 credit tier; national, no state level cut published).