Japanese Car Insurance Grade Premium Calculator

Enter your current voluntary car insurance premium and Japanese no-fleet grade to estimate the annual premium at another grade or accident coefficient. Includes a static grade 1-20 discount and surcharge table.

Japanese car insurance grade discount and surcharge table

Japanese no-fleet policies use grades 1 through 20. From grade 7, separate no-accident and accident coefficients apply. Negative figures are discounts and positive figures are surcharges.

Grade No accident Accident
1 grade +108% Not separate
2 grade +63% Not separate
3 grade +38% Not separate
4 grade +7% Not separate
5 grade -2% Not separate
6 grade -13% Not separate
7 grade -27% -14%
8 grade -38% -15%
9 grade -44% -18%
10 grade -46% -19%
11 grade -48% -20%
12 grade -50% -22%
13 grade -51% -24%
14 grade -52% -25%
15 grade -53% -28%
16 grade -54% -32%
17 grade -55% -44%
18 grade -56% -46%
19 grade -57% -50%
20 grade -63% -51%

Rates use the revised reference pure premium coefficients published by the General Insurance Rating Organization of Japan in June 2021. Actual application can vary by insurer and policy start date.

Tips

  • Check your policy certificate or insurer account for the annual premium, current grade, and remaining accident-coefficient period before entering the values.
  • To explore whether making a claim could cost more later, lower the current grade by three and select the accident coefficient as a common scenario. Some accidents lower the grade by one or do not count, so confirm the treatment with your insurer.
  • A first policy normally starts at grade 6. A qualifying second-car policy may start at grade 7, and a claim-free year generally raises the policy by one grade.
  • This comparison isolates only the grade effect. Your renewal premium can still change when the vehicle rating class, age band, coverage, or insurer base rates change.

Frequently asked questions

A first voluntary car insurance policy normally starts at grade 6. A second vehicle may start at grade 7 under the second-car discount when the existing policy and household meet the insurer's conditions.

A liability or collision claim generally lowers the next policy by three grades and applies the accident coefficient for three years. Theft or flying-object damage may lower it by one, while some benefits are no-count claims. Treatment depends on the accident and policy.

At grades 7-20, a policy in its post-claim period receives a smaller discount than a claim-free policy at the same numeric grade. A claim can therefore affect the price through both the lower grade and the accident coefficient.

Yes. Vehicle model rating class, driver age band, coverage, discounts, and insurer base rates also affect the premium. This calculator holds those factors constant so that you can see the grade effect alone.
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Side Note — The grade system looks mainly at claim count, not claim size

Japan's no-fleet grade system primarily reflects whether claims occurred and how many there were. In principle, a three-grade-down claim changes the next grade in the same way whether the insurer paid a modest repair bill or a very large loss. For a small claim, policyholders sometimes compare the payout with the extra premiums expected over the following years before deciding whether to claim.

The accident-coefficient period affects price separately from the grade reduction. A claim-free policy that reached grade 10 and a policy that fell from grade 13 to grade 10 can have the same grade number but different discounts. This calculator exposes grade and coefficient as separate choices so that both effects remain visible.

Actual premiums also reflect the loss experience of each vehicle model. Japanese regular and compact passenger cars have rating classes 1-17 for each coverage type, while kei passenger cars use classes 1-7, reviewed annually. Your renewal can therefore move even when you personally had no accident, which is why comparable quotes remain important.