Loss Ratio

A core underwriting profitability KPI. Lower is generally better; definitions of “incurred” (paid + reserves) must match your statutory or management report.

Loss ratio % = incurred losses ÷ earned premium × 100.

Tip: Keep “Incurred Losses” and “Earned Premium” on the same basis (period, units, and population) before calculating Loss Ratio.

Cluster: Insurance hub · Finance hub · Business hub · Percentage guide

Loss ratio compares incurred losses to earned premium for a book or period.

Enter incurred losses and earned premium for the same segment and window.

$
Paid losses + reserve changes (per policy)
$
Earned premium for the same period

Loss Ratio

Understanding Loss Ratio

How we calculate. Loss ratio % = incurred losses ÷ earned premium × 100. The form uses the same arithmetic as the worked examples on this page. See our methodology and accuracy policy.

Real-world scenario: A typical Loss Ratio case uses incurred losses 6500000 and earned premium 10000000. Enter the same figures below to reproduce the worked path.

What is Loss Ratio?

A core underwriting profitability KPI. Lower is generally better; definitions of “incurred” (paid + reserves) must match your statutory or management report.

  • Same book and period for both inputs
  • Earned premium—not written—unless you label written loss ratio
  • Pairs with expense and combined ratios

The Formula

Loss Ratio
Loss ratio % = (Incurred losses ÷ Earned premium) × 100

Worked Example

Scenario: Incurred losses $6,500,000; earned premium $10,000,000.
Step 1: 6500000 ÷ 10000000 = 0.65
Step 2: × 100 = 65%
Answer: Loss ratio is 65%.

Common Use Cases

  • Underwriting reviews: book profitability
  • Product pricing: loss experience
  • Board packs: segment loss trends

Pro Tips

  • State paid vs incurred
  • Watch reserve strengthening spikes
  • Don’t mix currencies

Limitations: Loss Ratio results are educational insurance and agency planning aids—not underwriting, actuarial, claims, or financial advice. Confirm statutory definitions with your carrier, regulator, and finance teams.

FAQ

Written or earned premium?

Standard loss ratio uses earned premium. Written premium needs a labeled written loss ratio.

What if earned premium is 0?

Loss ratio is undefined—enter positive earned premium.

Authoritative References

For insurance ratio and reporting concepts, consult: