Loss Ratio Calculator

Calculate the loss ratio — the percentage of premiums used to pay claims and adjustment expenses — to evaluate insurance underwriting profitability.

Total claims paid plus reserves for outstanding claims during the period.
Costs to investigate and settle claims (allocated + unallocated). Leave blank to calculate pure loss ratio.
Portion of written premiums corresponding to the expired part of the policy period.

Formulas

Pure Loss Ratio

Loss Ratio = Incurred Losses / Earned Premiums

Loss & LAE Ratio (Combined with Adjustment Expenses)

Loss & LAE Ratio = (Incurred Losses + Loss Adjustment Expenses) / Earned Premiums

Incurred Losses = Losses Paid + Change in Loss Reserves
Earned Premiums = Written Premiums − Change in Unearned Premium Reserve

A loss ratio of 60–70% is generally considered the industry benchmark for a profitable line of business, though this varies by line (e.g., workers' comp vs. auto vs. health).

Assumptions & References

  • The loss ratio alone does not indicate overall profitability; the combined ratio (loss ratio + expense ratio) provides a fuller picture.
  • References: NAIC Glossary of Insurance Terms; Insurance Information Institute (III) — How the Insurance Industry Works; CAS Exam Study Notes on Ratemaking (Friedland, 2010).

In the network