Free loss ratio calculator
Enter incurred losses, loss adjustment expense and earned premium to get the loss ratio — the share of premium an insurer pays out as claims — with the premium retained and a plain-English reading of the band, updated live, as you type.
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Estimate only, based on the figures you enter. Not actuarial, accounting or regulatory advice.
Results are estimates. Consult a professional.
What is the loss ratio?
The loss ratio is the share of the premium an insurer earns that it pays back out as claims. It is one of the first numbers underwriters, analysts and regulators look at, because it tells you — in a single percentage — how much of every premium dollar a book of business is spending on the losses it was bought to cover. A loss ratio of 70% means 70 cents of every earned premium dollar went to claims and the cost of handling them; the other 30 cents was left to cover the insurer's own expenses and profit. This loss ratio calculator returns that percentage the moment you enter incurred losses, loss adjustment expense and earned premium.
Who uses the loss ratio, and why
The loss ratio is a working number for several different readers, each asking a slightly different question of the same figure:
- Underwriters and actuaries use it to judge whether the premium charged is adequate for the claims the book is producing — and whether rates need to rise.
- Insurer management and investors read it as the first half of the combined ratio, the headline measure of whether the insurance side of the business is profitable.
- Regulators, especially in health insurance, set minimum loss ratios so that policyholders get fair value for their premium.
- Policyholders and brokers occasionally look at it to gauge how a carrier prices a line of business, though carrier-level ratios are not a guide to any one person's premium.
The three inputs explained
- Incurred losses. Not just the cheques written this period — it is claims paid plus the change in case and IBNR reserves (losses incurred but not yet reported). This is what makes the ratio reflect the losses that belong to the period, not just the ones settled in it.
- Loss adjustment expense (LAE). The cost of running claims: adjusters, investigators, legal defence and the claims department's overhead. Including it gives the loss-and-LAE ratio; leave it at zero for the pure loss ratio. The combined figure is the more complete view.
- Earned premium. The portion of premium that matches coverage already provided. A one-year policy written today has earned only a fraction of its premium by next month — earned premium, not written premium, is the correct denominator.
A worked example using the loss ratio calculator
Over a year, a line of business earns $1,000,000 in premium. It incurs $650,000 of losses and spends $50,000 on loss adjustment expense settling those claims. What is the loss ratio?
Step 1 — Add the numerator
Incurred losses plus LAE is $650,000 + $50,000 = $700,000. This is the total cost of claims for the period.
Step 2 — Divide by earned premium
Loss ratio = $700,000 ÷ $1,000,000 = 0.70, or 70%. The remaining 30% of premium is what is left to pay the insurer's own expenses and earn a profit.
How to read your loss ratio
There is no single "good" loss ratio — it depends on the line of business and the expense load that sits on top of it. But the bands below are a useful starting frame, and they show why both a very low and a very high ratio can be a warning.
| Loss ratio | What it usually signals |
|---|---|
| Under 50% | Claims are light and premium is being retained — but a persistently low ratio can mean the insurer is over-pricing, under-paying valid claims, or (in regulated health markets) breaching a minimum loss ratio rule. |
| 50% – 70% | A comfortable underwriting margin for most P&C lines, leaving room for expenses and profit. |
| 70% – 80% | A common target range: profitable once expenses are reasonable, but with little cushion for a bad year. |
| 80% – 100% | Claims-heavy. Premium still covers losses, but the margin for expenses is thin or gone — the combined ratio may already be above 100%. |
| Over 100% | An underwriting loss: claims plus LAE alone exceeded premium, before any expenses. The book is losing money on insurance and relies on investment income to stay afloat. |
General guidance, not a regulatory standard. Acceptable loss ratios vary widely by line — a low-expense line can tolerate a higher loss ratio than a high-commission one.
Loss ratio vs. combined ratio
The loss ratio is only half the profitability picture. It ignores the insurer's own running costs — commissions, salaries, marketing and overhead — which the expense ratio captures. Add the two together and you get the combined ratio, the headline test of underwriting profit.
The ACA Medical Loss Ratio (a regulated cousin)
In US health insurance the loss ratio is more than an analyst's metric — it is the law. The Affordable Care Act's Medical Loss Ratio (MLR) rule requires health insurers to spend at least 80% of premium (in the individual and small-group markets) or 85% (large-group) on medical claims and quality-improvement activities. Insurers that fall short must rebate the difference to policyholders.
Common mistakes to avoid
- Using written premium instead of earned premium. Written premium overstates the denominator early in a policy term and understates the ratio. Always use earned premium.
- Forgetting reserve changes. Incurred losses are not just paid claims — they include the change in reserves. A book that looks great on paid losses can have a much higher incurred loss ratio once IBNR reserves are added.
- Confusing the pure and loss-and-LAE ratios. Quoting a 65% pure loss ratio against a competitor's 72% loss-and-LAE ratio is not a fair comparison. State which one you mean.
- Reading a single period as the trend. One catastrophe or one large claim can spike a small book's loss ratio. Multi-year or industry-segment ratios are more stable.
- Treating it as the ACA MLR. The general loss ratio and the regulatory Medical Loss Ratio use different numerators and denominators — see the section above.
Loss ratio definitions
How accurate is this loss ratio?
The arithmetic is exact for the three figures you enter — divide losses plus LAE by earned premium and you have the ratio. The judgement is all in the inputs. Real incurred losses depend on reserving assumptions that actuaries revise as claims develop, so the same book can show a different loss ratio depending on the valuation date and the reserve methodology. Earned premium also depends on how unearned premium is calculated.
Treat the result as an analytical estimate for understanding a book of business or comparing lines — not a statutory filing figure or a regulatory MLR calculation. For reported ratios, use audited financial statements; for the ACA MLR, follow the federal definition and reporting forms.
Insurance Information Institute — glossary and industry financial ratios.CMS — Medical Loss Ratio program.Frequently asked questions about the free loss ratio calculator
About this Loss ratio calculator
This loss ratio calculator runs entirely in your browser — the figures you enter are never stored or sent anywhere. It applies the standard definition (incurred losses plus loss adjustment expense, divided by earned premium) and recomputes the loss ratio, the numerator and the premium retained the instant you change a field. It is an analytical estimate, not a statutory filing or a regulatory Medical Loss Ratio calculation.
It is one of our free insurance calculators. Pair it with the combined ratio calculator for the full underwriting-profit picture, or browse the complete calculators directory.