Vehicle Weight Tax Calculator (Japan)
Select your vehicle weight class (for regular/compact cars) or kei car, the inspection type (new registration or renewal), and the eco-car tax reduction category to estimate Japan's vehicle weight tax, including the 13-year and 18-year aged-vehicle surcharge.
What Is Japan's Vehicle Weight Tax?
Japan's vehicle weight tax (jidosha juryozei) is a national tax paid at vehicle inspection (new registration or renewal inspection), based on the vehicle's weight. Just by choosing your vehicle type (regular/compact car or kei car), weight bracket, inspection type, and eco-car reduction category, this tool instantly estimates the tax due, the period it covers, and the equivalent yearly amount.
Regular and compact cars are taxed using a table based on 0.5-tonne weight brackets, while kei cars use a flat rate regardless of weight. Because the eco-car reduction is decided only once, at new registration, we recommend double-checking the amount shown on your vehicle inspection certificate or tax notice when estimating a renewal inspection.
How to Use the Vehicle Weight Tax Calculator
- Choose your vehicle type Select "Regular/compact car" or "Kei car." Each uses a different tax table based on vehicle weight.
- Choose your weight bracket For regular/compact cars, round up to the nearest 0.5-tonne bracket shown on your inspection certificate. Not needed for kei cars.
- Choose the inspection type Select "New registration (3 years)" for a brand-new car, or "Renewal inspection (2 years)" for any shaken after that.
- Choose the eco-car reduction category Pick the category that applies: exempt, 50% reduction, 25% reduction, standard rate, or (for renewals only) the 13-year or 18-year aged-vehicle surcharge.
- Check the result The estimated tax, covered period, and per-year equivalent appear automatically, and update instantly as you change your inputs.
Tips for getting more out of it
- Check the "vehicle weight" field on your vehicle inspection certificate (shaken-sho) and choose the nearest bracket rounded up (e.g. 0.5t or less, 1.0t or less).
- Choose "New registration (3 years)" right after buying a brand-new car, and "Renewal inspection (2 years)" for every shaken after that.
- The eco-car reduction category is decided only at first registration. To confirm which category applies at a renewal inspection, check the tax amount printed on your shaken paperwork or tax notice.
- For kei cars at renewal inspection, this tool does not support the 50%/25% reduction tiers because reliable sources disagreed on the exact amounts. Only exempt, standard, over-13-year, and over-18-year are supported.
- The aged-vehicle surcharge (13-year / 18-year) applies uniformly to older cars regardless of environmental performance, and can never apply together with the eco-car reduction.
When This Calculator Helps
Checking a shaken quote
Verify whether the vehicle weight tax listed on a garage or dealer's inspection quote is reasonable given your vehicle's weight and eco-car category.
Estimating costs for a new car
Compare the weight tax due at new registration across different eco-car reduction categories when budgeting for a new vehicle.
Reviewing running costs for an older car
See how much the 13-year or 18-year aged-vehicle surcharge adds, to help weigh keeping your current car against replacing it.
Comparing kei cars and regular cars
Estimate both under the same inspection type and eco-car category to compare running costs when choosing a vehicle.
Glossary
- Vehicle weight tax
- A national tax paid at vehicle inspection (new registration or renewal), based on vehicle weight. Introduced in 1971 to help fund road maintenance.
- New registration inspection
- The inspection performed when a new car is first registered. Passing it means paying three years of vehicle weight tax at once.
- Renewal inspection (shaken)
- The periodic inspection required for an already-registered car to keep using public roads. Passing it means paying two years of vehicle weight tax at once.
- Eco-car reduction
- A scheme that exempts or reduces (by 50% or 25%) the vehicle weight tax based on fuel-efficiency standards. It is decided mainly at new registration, and the standards are revised every few years.
- Standard rate
- The regular vehicle weight tax rate, applied when neither the eco-car reduction nor the aged-vehicle surcharge applies — for example, to non-eligible vehicles or once a reduction period has ended.
- Aged-vehicle surcharge
- An increased vehicle weight tax rate applied uniformly, regardless of environmental performance, once 13 or 18 years have passed since new registration. It never applies together with the eco-car reduction.
- Weight bracket
- The basis for calculating regular/compact car vehicle weight tax — the vehicle weight shown on the inspection certificate, rounded up to the nearest 0.5-tonne increment.
Frequently asked questions
Side Note — Why the vehicle weight tax is based on weight
The vehicle weight tax was created in 1971 to fund road construction and maintenance, on the reasoning that heavier vehicles put more strain on paved roads — hence weight as the tax base. It was originally an earmarked tax dedicated to road projects, but a 2009 tax reform folded it into general revenue, so today the money can be used for any government purpose.
The eco-car tax reduction was introduced in 2009 to encourage owners to switch to more environmentally friendly vehicles. It grants exemption, 25%, 50%, or (for kei cars only) 75% reductions depending on how far a vehicle exceeds current fuel-efficiency standards — and because those standards are revised every few years, a model that once qualified can lose its eco-car status after the benchmark is tightened.
The 13-year and 18-year aged-vehicle surcharge works in the opposite direction, raising the tax burden on older cars. Owners who carefully maintain the same vehicle for many years sometimes object to paying more purely because of its age, regardless of how well it still runs, which keeps this policy a recurring topic of debate between environmental goals and the realities of long-term car ownership.