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.
What the break-even point between claiming and paying yourself is
Claiming on your own-damage cover pays for the repair, but your grade falls the following year and the premium rises. The break-even point is **where the payout and the accumulated increase in premium come level**. Enter the repair cost, the deductible, your current grade and annual premium, and the accident category, and this tool lays out **the next ten years** year by year, showing in which year the accumulated increase overtakes what you received.
**The drop in grade for each accident category counts the one grade you would otherwise have gained.** A three-grade accident therefore opens a gap of four grades in effect, a one-grade accident two, while a no-count accident advances exactly as a clean year would. The accident-rate period runs three years, one year and none respectively. **The estimate presumes your current policy sits on the no-accident rate**, holds the vehicle category, model rating class, age condition and scope of cover constant, and **does not allow for a second accident during the accident-rate period.**
How to use the simulator
- Enter the repair cost and the deductible The repair cost goes in units of ten thousand yen, the deductible in yen. **Where the deductible equals or exceeds the repair cost there is nothing to receive**, so claiming would serve no purpose.
- Enter your current grade and annual premium Take them from the policy schedule. From these two the tool works back to the premium before the grade discount and rebuilds each year’s figure.
- Choose the accident category Pick three-grade (liability and own damage), one-grade (theft, a stone chip and the like) or no-count (legal expenses cover and the like).
- Read the break-even year from the table The grades under self-payment and under a claim sit side by side for each year, with the increase and its running total. The year the total passes the payout is the break-even point.
- If it never passes within ten years, claim A result reading “does not exceed within the projection” means the increase cannot catch the payout even over a decade.
Tips for getting more out of it
- 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.
Where the simulator helps
When you are unsure about a small repair
Dropping three grades for a repair of a few tens of thousands of yen usually costs more than paying it. This draws the line in money.
When a costly repair makes the call hard
The larger the repair, the larger the payout, and ten years of increase may not overtake it.
When your grade is high and you want to tread carefully
The nearer grade 20, the larger the discount — and the larger the increase when it falls. That side has more to lose.
When checking which accident category applies
A stone chip or a theft is one grade; legal expenses cover is no-count. A different category gives a different conclusion.
When you want the effect of the terms themselves
For premiums by grade, see the grade premium simulator; for the excess, the deductible impact calculator; for who may drive, the driver-scope endorsement comparison.
Terms about the break-even point
- Break-even point
- The moment at which the payout received and the accumulated rise in premium come to the same figure. Past it, having claimed leaves you worse off.
- No-fleet grade
- The system in which a grade from 1 to 20 sets the loading or discount on the premium. A clean year raises it by one; claiming after an accident lowers it.
- Three-grade accident
- The category for a claim on liability or own-damage cover. Together with the one grade otherwise gained, it opens a gap of four grades in effect.
- One-grade accident
- The category for limited cases such as theft or a windscreen broken by a stone. It opens a gap of two grades in effect.
- No-count accident
- The category in which a claim — on legal expenses cover, for instance — leaves the grade untouched. It rises just as it would after a clean year.
- Accident-rate period
- The span over which the less generous “accident” rate applies at the same grade. It runs three years after a three-grade accident and one after a one-grade accident.
- Deductible
- The sum you bear yourself when claiming on own-damage cover. What remains of the repair cost after subtracting it is the payout.
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.