Massachusetts car excise tax costs $25 for every $1,000 of your car's assessed value. The RMV sets the value from the original MSRP and the car's age. Your town bills you based on where you garage the car.
For a 2020 Mazda CX-3 taxed in 2024, the car falls in its fifth year. You use 10% of the original MSRP as the base value.
RMV age schedule
| Vehicle age | Percentage of original MSRP |
|---|---|
| Year before model year | 50% |
| Model year | 90% |
| Second year | 60% |
| Third year | 40% |
| Fourth year | 25% |
| Fifth year and older | 10% |
2020 Mazda CX-3 MSRP examples
| Trim | MSRP |
|---|---|
| Sport | $21,300 |
| Touring | $23,300 |
| Grand Touring | $28,880 |
Step-by-step for 2020 Mazda CX-3 Touring
- Find assessed value: $23,300 MSRP x 10% = $2,330.
- Calculate full-year tax: $2,330 / 1,000 x $25 = $58.25.
- Prorate for partial year: Multiply by months registered / 12. Register in June? Use 7/12. $58.25 x 7/12 = $34.00.
Follow these rules to get it right:
- Pay at least $5, even if math shows less.
- Count a full month if you register any day in it. Same for canceling plates.
- Your town mails the bill after RMV processes registration. Pay within 30 days to skip interest and fees.
- Update your garage address with RMV if you move.
- Sell, trade, junk, total, or move out of state? Ask your town for abatement or credit.
Quick formula
- Assessed value = original MSRP x age percent.
- Full excise = assessed value / 1,000 x $25.
- Prorated = full excise x (months / 12).
Find MSRP on RMV valuation lists, window sticker, manufacturer sites, or registration papers. Match your exact trim and options.
This applies to passenger cars and light trucks. Sidekick tracks your excise tax and adds it to your ownership budget to help you plan ahead.