Claims-cost ratio showing how much earned premium is consumed by losses.
Loss ratio measures how much earned premium is being consumed by claims costs. It is one of the most common actuarial and underwriting yardsticks used to judge whether a book of business is behaving as expected.
In many insurer discussions, “losses” means incurred losses, not just cash already paid.
Loss ratio is one of the clearest bridges between consumer-facing insurance language and insurer economics. It helps explain why certain segments harden, why rates change, and why some books of business become harder to place or renew.
It also helps readers understand why premium changes cannot be judged only from the declarations page. A book with persistent water-damage losses, bodily-injury deterioration, or catastrophe activity will eventually show that pressure in its loss ratio.
Canadian insurers, actuaries, brokers, and underwriters use loss ratio when they are discussing:
At a simple level, a higher loss ratio means more of the earned premium is being consumed by claims. That does not automatically tell the whole story, but it is often the first number people reach for.
| Measure | Numerator | Denominator | What it answers |
|---|---|---|---|
| Loss ratio | Incurred losses | Earned premium | How much premium is being used up by claims? |
| Expense ratio | Underwriting expenses | Premium base | How much premium is being consumed by operating cost? |
| Combined ratio | Losses plus expenses | Earned premium | Is underwriting profitable before investment income? |
Loss ratio is also different from loss reserve. A reserve is an estimated amount held for claim obligations. Loss ratio is a comparative performance measure.
If an insurer reports CAD 12 million in earned premium on a property portfolio and CAD 8.4 million in incurred losses, the loss ratio is 70%.
That figure is useful because it tells readers that claims alone are absorbing 70 cents of every earned-premium dollar before expenses are added. If claims costs rise to CAD 10.2 million on the same premium base, the loss ratio rises to 85%, which usually signals serious pricing or underwriting pressure.
Loss ratio is not the same as profit. An insurer can still report a weak underwriting result even when the loss ratio looks manageable if the expense base is heavy.
It is also wrong to treat the ratio as a consumer refund or value measure. A low loss ratio does not mean a policyholder paid “too much.” It means the insurer’s claims costs were relatively low compared with earned premium over that period.
Readers also sometimes compare loss ratios from different books without checking whether the time period, catastrophe experience, exposure mix, or reserving basis is comparable.
Loss ratio is only as useful as the underlying claims and premium data. Reserve development, catastrophe years, reinsurance structure, and unusual claims inflation can all make the number more nuanced than the headline percentage suggests.