Japanese Car Insurance Claim vs Self-Pay Break-Even Simulator
Enter your repair cost, deductible, Japanese no-fleet grade, and premium to project 10 years of grade-drop premium increases and find the break-even year against paying for repairs yourself.
Grade Impact and Accident-Having Period by Accident Category
How much your grade drops next year, and how long the accident-having factor applies, both depend on the type of accident.
| Accident category | Impact on grade | Accident-having period |
|---|---|---|
| 3-grade-down accident | Grade drops by 3 next year (effectively a 4-grade swing once you count the +1 you would otherwise have earned) | 3 years |
| 1-grade-down accident | Grade drops by 1 next year (effectively a 2-grade swing once you count the +1 you would otherwise have earned) | 1 year |
| No-count accident | Grade rises by 1 just as it would with no accident (using insurance has no effect on the grade) | Not applicable |
The grading system and accident-having period rules follow guidance from Japan's General Insurance Rating Organization and the General Insurance Association of Japan. Grade-level surcharge/discount rates use the reference pure premium rates the Rating Organization published after its June 2021 revision.
Usage Tips
- Check your policy document or online account for your current annual premium and grade before entering them — your grade is listed under the "non-fleet grade" field.
- If you are unsure which accident category applies, ask your insurer's claims desk; as a rule of thumb, liability and collision-type claims are "3-grade-down," while limited-coverage claims like theft or vandalism are "1-grade-down."
- The deductible is the amount you agreed to pay out of pocket when you signed up. If you are not sure, check the "deductible" field on your policy document.
- This simulation isolates only the effect of the grade and accident surcharge. It does not include other premium factors, such as a revision to your vehicle's rating class.
Frequently Asked Questions
Side Note — Why People Say "Claiming Small Accidents Isn't Worth It"
Japan's non-fleet grading system sets next year's grade based only on whether — and how many times — you filed a claim, not on how much was paid out. That means a small accident costing a few hundred dollars in repairs and a large accident costing tens of thousands both lower your grade the same way if both are classified as "3-grade-down." The smaller the repair cost, the more likely the cumulative premium increase will exceed the payout, which is exactly why people say claiming for small accidents "isn't worth it."
Beyond the grade drop itself, the accident-having period is easy to overlook. Two contracts at the same grade can have different discount rates depending on whether that grade was reached without any accidents or reached after a drop from a claim. This gap adds to your premium for 3 years after a 3-grade-down accident, or 1 year after a 1-grade-down accident, so the real cost is larger than simply "losing three grades" would suggest.
On the other hand, for accidents involving large payouts — like bodily injury liability — claiming is usually still worthwhile even after subtracting the future premium increase. Because the grading system tracks the number of accidents rather than their size, using insurance makes the most sense for costly accidents, while self-pay becomes a real option worth weighing for smaller ones.