What Is a Loss Ratio in Insurance?

A loss ratio is incurred losses divided by earned premium, expressed as a percentage; it is the single number underwriters read to judge whether an account has cost more in claims than it brought in through premium. A lower loss ratio generally supports better renewal pricing, while a ratio near or over 100% signals the account has been paying out more than it took in.

How loss ratio is calculated

The calculation is straightforward: total incurred losses for a period (claims paid plus amounts reserved for open claims) divided by the earned premium for that same period. A business with $30,000 in incurred losses against $100,000 in earned premium has a 30% loss ratio for that period. The figure comes directly from the loss run a carrier provides.

Reading the number

There is no single "good" loss ratio that applies across every line of coverage, since carriers price different lines with different expected loss ratios built in. What matters more consistently is the trend: a loss ratio climbing year over year, even if still under 100%, is a pattern an underwriter will ask about, while one holding steady or improving supports the case for flat or better pricing at renewal.

Loss ratio and claims frequency together

Loss ratio can be pushed up by one large claim or by many smaller ones, and the two read differently even at the same ratio. A single severe claim against otherwise clean years often prices differently than several moderate claims totaling the same amount, because the pattern behind the number matters as much as the number itself. Tracking how claims affect premiums covers why frequency often concerns underwriters more than a single severe loss, even when the loss ratio math looks similar.

Tracking loss ratio over time

Because loss ratio is read across multiple years, not just the current term, keeping historical loss runs and claims data in one place is what makes the trend visible instead of reconstructed from old paperwork each renewal. Atlasafe imports the loss runs you upload and computes loss ratio from that data, alongside the claims you record with their status, so the figure is ready before a broker or underwriter asks for it.