Quick Answer: A $35,000 vehicle in Wyoming with $5,000 cash down, a 60-month term, and a 7.25% APR carries a $626.36 monthly payment at the 4% state rate with no county option tax. That figure includes $1,400.00 of sales tax and $45.00 in title and state registration, financing $31,445.00 in total. Add a 2% county option tax and the payment rises to $640.31. Confirm your county's rate with the county treasurer, since this page does not publish one.
Overview
Wyoming has the lowest state sales tax rate in the Rocky Mountain West at 4%, and on a car that headline is close to the whole story at the point of purchase. What it leaves out is where Wyoming actually collects money from vehicle owners, which is the annual county registration fee rather than the sale.
Start with the purchase. Wyo. Stat. § 39-15-104 sets the state rate at 4%. Counties may add general purpose, specific purpose, economic development, and resort district option taxes on top, which in practice run from nothing to about 2%. There is no reduced automotive rate, so a car carries the same combined rate as anything else you buy.
The sourcing rule is unusually strict and unusually easy to get wrong. The rate charged is the one in effect in the county of the owner's principal residence as shown on the driver's license or government ID, on the date of sale. Not the dealer's county. Not the county where the tax gets remitted. If the dealer did not collect the tax, the county treasurer collects it from you before the vehicle can be registered for the first time, and they will apply your home county's rate.
Now the part that costs more over time. Wyoming's county registration fee is value-based, computed from the vehicle's original factory cost rather than what you paid, and it recurs every year. On a car with a $35,000 original factory cost, the first-year county fee is $630, and it is charged again every year at a declining rate that stops falling in year six. Over a five-year ownership period it adds up to more than the one-time state sales tax on the purchase. Anyone comparing Wyoming to a neighboring state on the strength of the 4% rate alone is comparing the wrong number.
Auto Loan APR by Credit Score
The APR columns below are national averages, not Wyoming 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 Wyoming, because it runs this calculator's own Wyoming tax and fee rules at each tier's rate.
| Credit Tier | VantageScore 4.0 | Avg New APR | Avg Used APR | Est. Payment in Wyoming |
|---|---|---|---|---|
| Super prime | 781-850 | 4.55% | 6.30% | $586.94 |
| Prime | 661-780 | 6.23% | 8.77% | $611.29 |
| Nonprime | 601-660 | 9.67% | 14.03% | $663.02 |
| Subprime | 501-600 | 13.44% | 19.42% | $722.57 |
| Deep subprime | 300-500 | 16.01% | 21.77% | $764.85 |
Payment assumptions: $35,000 vehicle price, $0 trade-in, $5,000 cash down, $0 dealer documentation fee, 60-month term, new-vehicle APR applied to the Wyoming delivered price including tax and statutory fees. At the 6.39% overall new-car average the same purchase costs $613.64 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.
What Moves Your Payment
Each row changes one input and leaves the rest at the baseline below. The dollar effects are this calculator's own output for Wyoming, not a rule of thumb.
| Factor | What Changes | Effect on Monthly Payment | Effect on Total Interest |
|---|---|---|---|
| Vehicle Price | Each extra $1,000 of price raises both the amount financed and the sales tax base, so the tax rises with it. | +$20.72 | +$202.97 |
| Trade-In Allowance | A $1,000 allowance cuts the amount financed by $1,000 and reduces the sales tax base by the same amount, so it saves tax as well as principal. | -$20.71 | -$202.97 |
| Cash Down Payment | A $1,000 larger down payment cuts the amount financed by $1,000. It never reduces the sales tax, which is assessed on the price, not on what you borrow. | -$19.92 | -$195.16 |
| Dealer Doc Fee | A $100 higher documentation fee adds $100 to the amount financed. It sits outside the sales tax base in Wyoming, so it does not raise the tax. | +$2.00 | +$19.52 |
| Longer Term | Stretching the same balance from 60 months to 72 months spreads the principal over twelve more payments at the same rate. | -$86.47 | +$1,290.14 |
Baseline: $35,000 vehicle price, $0 trade-in, $5,000 cash down, $0 documentation fee, 60 months at 7.25% APR, giving a $626.36 payment and $6,136.96 of total interest.
How This Is Calculated
Wyoming's county treasurer collects 4% plus the county option tax, at your county of principal residence, before first registration. Five steps.
1. Net taxable sales price. Wyo. Stat. § 39-15-105 excludes the trade-in value of tangible personal property from the sales price of new tangible personal property when the trade and the purchase happen in one transaction. There is no dollar cap.
The allowance cannot exceed the price of the car you are buying, so an oversized trade takes the base to zero rather than below it.
2. Sales tax. The 4% state rate plus your county option tax, applied at your county of principal residence.
3. Title and state registration. A fixed $45, being a $15 title fee and the $30 state portion of passenger car registration. Trucks pay more by gross weight, up to about $90 above 6,001 pounds.
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.
Why No County Rate Is Published Here
Wyoming's county option tax rates are published by the Excise Tax Division as a downloadable master rate chart, and the county treasurer sites that would corroborate them were not reachable. Rather than print a rate for Cheyenne, Casper, Gillette, Rock Springs, or Jackson that might be stale or simply wrong, this calculator asks you for it and leaves the default at zero.
What can be said: the statewide average county add-on is reported around 1.3%, and the highest combined general rates in the state are in Teton County resort districts. Whether a resort district tax reaches a motor vehicle sourced to a buyer's residence is not settled in the material available, so Jackson-area buyers in particular should ask the Teton County treasurer directly rather than assume either way.
Call your county treasurer, ask for the current combined rate for a vehicle titled to a resident of your county, and enter that figure. It takes one phone call and it is the difference between an estimate that is right and one that is off by up to $700 on a $35,000 car.
The County Registration Fee
This is the Wyoming vehicle cost that surprises people, and it is not part of the purchase at all.
Alongside the $30 state registration, the county charges an annual fee computed as:
Factory cost means the vehicle's original MSRP, not your negotiated price and not its current market value. The year-of-service rate declines: 60% in year one, 50% in year two, 40% in year three, 30% in year four, 20% in year five, and 15% from year six onward, where it stops.
A vehicle with a $20,000 factory cost therefore owes $20,000 × 0.60 × 0.03, or $360, in its first year. The same vehicle in its sixth year owes $20,000 × 0.15 × 0.03, or $90, and it stays at $90 for as long as you own it. The floor is the part worth planning around: unlike a true depreciating property tax, the Wyoming county fee never falls below 15% of original factory cost as its multiplier base.
None of this is financed into the loan and none of it appears in the figures on this page.
Worked Example
Wyoming's 4% state rate is collected by the county treasurer before your first registration, and counties may add an optional tax on top. The state figure alone comes first, then a 2% county.
- Vehicle price: $35,000
- Trade-in allowance: $0
- Cash down: $5,000
- Dealer doc fee: $0
- County option tax: 0%
- Term: 60 months at 7.25% APR
Step 1 -- The taxable sales price. Sales price excluding the trade-in value taken in the same transaction: $35,000 - $0 = $35,000.00
Step 2 -- Wyoming sales tax at 4%. $35,000.00 x 4% = $1,400.00
Step 3 -- Title and state registration, outside the base. $15.00 title + $30.00 registration = $45.00
Step 4 -- Total delivered price. $35,000 + $1,400.00 + $45.00 = $36,445.00
Step 5 -- Amount financed. $36,445.00 - $0 trade-in - $5,000 cash down = $31,445.00
Step 6 -- The monthly payment. $31,445.00 at 7.25% over 60 months = $626.36
Step 7 -- Month 1. $31,445.00 x (7.25% / 12) = $189.98 interest, $436.38 principal, balance $31,008.62
Step 8 -- Month 2. $31,008.62 x (7.25% / 12) = $187.34 interest, $439.02 principal, balance $30,569.60. Cumulative interest: $377.32
Step 9 -- The accumulation. Interest through month 12 is $2,102.21 with $26,030.89 outstanding. Over the full term, $6,136.96
Put the same buyer in a county charging a 2% option tax and the combined rate is 6%. Tax rises to $2,100.00, the financed balance to $32,145.00, and the payment to $640.31. That is $700 of extra tax purely from the county line on your driver's license.
Add a $10,000 trade-in at the state rate alone and the taxable price drops to $25,000, tax to $1,000.00, and the payment to $419.20. The trade-in saved $400 in tax. In a 2% county the same trade-in saves $600.
What This Does Not Account For
- The annual county registration fee. It is value-based on original factory cost, recurs every year, and is far larger than the $30 state portion. It is described above rather than included, because it depends on MSRP and years of service rather than on your purchase.
- County option tax rates. No rate is asserted for any Wyoming county. The default is 0%, which is the floor, not a typical figure. Enter your own.
- Dealer documentation fee taxability. Wyoming sets no cap, publishes no typical figure, and its treatment of a separately stated doc fee in the sales price was not confirmed. The input starts at $0, and any amount you enter is added to the delivered price but not taxed. If your dealer taxes it, add your combined rate on the fee.
- Resort district taxes. Teton Village and Alta are reported at the state's highest combined general rate. Whether that reaches a vehicle sourced to a buyer's residence is unresolved.
- Weight-based state registration above a passenger car, which scales toward about $90 for trucks over 6,001 pounds.
- GAP insurance, service contracts, and aftermarket add-ons, unless you fold them into the vehicle price yourself.
Common Pitfalls
- Using the dealer's county rate. Wyoming sources vehicle tax to the county of your principal residence as shown on your ID, on the date of sale. Buying in a low-rate county does not lower your bill.
- Assuming the dealer collected the tax. If they did not, the county treasurer collects it from you before first registration, and the vehicle cannot be registered until it is paid. Check your paperwork rather than discovering this at the counter.
- Budgeting only the 4%. The county option tax can add up to roughly half again on top, and the annual county registration fee dwarfs both over a few years of ownership.
- Expecting the county fee to track your purchase price. It is computed from original factory cost. Buying a heavily discounted or high-mileage used car does not reduce it, because the multiplier follows years of service rather than what you paid.
- Expecting the county fee to keep falling. The year-of-service rate stops at 15% in year six and stays there for the life of the vehicle.
- Judging the loan by the payment. Stretching this $31,445 balance from 60 to 72 months drops the payment to $539.89 and raises total finance charges from $6,136.96 to $7,426.96.
Frequently Asked Questions
What is Wyoming's sales tax rate on cars?
Which county's rate applies if I buy out of county?
Does a trade-in reduce sales tax in Wyoming?
How is the Wyoming county registration fee calculated?
Who collects the tax if the dealer does not?
Are Wyoming dealer documentation fees capped?
Sources
- Wyoming Department of Revenue, Excise Tax Division, sales and use tax rate charts. revenue.wyo.gov
- 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
Also consulted: Wyo. Stat. § 39-15-104 (4% state sales tax) and §§ 39-15-107 / 39-16-107 (collection by the county treasurer before first registration); Wyo. Stat. § 39-15-105 (trade-in exclusion from the sales price); Wyoming county treasurer fee schedules and guidance (Natrona, Sweetwater, Uinta, Goshen, Platte) for title fee, state registration, and the value-based county registration formula; 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).