Published October 2026.
Direct Answer: The combined ratio is the share of each premium dollar a carrier spends on claims and underwriting operations. Loss ratio plus expense ratio equals combined ratio: one figure for whether underwriting itself earned or lost money. Below 100 means underwriting profit on that book; above 100 means underwriting loss before investment income. It does not by itself prove the company is profitable overall, and it is among the first metrics analysts use when judging position in the insurance underwriting cycle.
When a renewal reprices and someone cites the carrier’s “98,” they mean combined ratio. What follows is the arithmetic line by line, scenarios at 105 and 92, and why 100 is not the full story.
What the combined ratio measures
Combined ratio states underwriting result—profit or loss on insurance operations—as a percentage of earned premium. Earned premium is written premium recognized for the period measured, after unearned premium is held for policies still in force.
Combined ratio = (Incurred losses + Underwriting expenses) ÷ Earned premium
Combined ratio = Loss ratio + Expense ratio
Premium is always the denominator. The same loss dollar produces a higher ratio when premium shrinks and a lower ratio when rate and exposure grow the base. Two carriers with identical incurred losses can report different combined ratios if earned premium diverges.
Combined ratio 100 is underwriting break-even: losses plus expenses equal premium, so underwriting profit is zero. Each point below 100 is roughly one cent of underwriting margin per premium dollar, before tax and non-underwriting items. Above 100, underwriting burns margin unless something else—usually investment income on float—fills the gap.
Combined ratio excludes investment income, taxes, and realized investment gains. Reserve moves still flow through incurred losses and can reflect prior accident years.
Loss ratio plus expense ratio — the two components
Both components divide by the same earned premium.
Loss ratio
Incurred losses are paid losses plus the change in case and IBNR reserves for the period.
Loss ratio = Incurred losses ÷ Earned premium
On $100 million earned premium with $72 million incurred losses:
$72,000,000 ÷ $100,000,000 = 0.72 = 72% loss ratio
Expense ratio
Underwriting expenses include acquisition (commissions, brokerage, premium taxes where expensed), general expenses allocated to the line, and overhead. Loss adjustment expense is typically inside incurred losses, not the expense ratio.
Expense ratio = Underwriting expenses ÷ Earned premium
On the same $100 million book with $26 million expenses:
$26,000,000 ÷ $100,000,000 = 0.26 = 26% expense ratio
72% + 26% = 98% combined ratio
$100,000,000 − $72,000,000 − $26,000,000 = $2,000,000 underwriting profit
(100% − 98%) × $100,000,000 = 2% × $100,000,000 = $2,000,000
The full worked example on $100 million of premium
| Item | Amount | Ratio |
|---|---|---|
| Earned premium | $100,000,000 | 100% |
| Incurred losses | $72,000,000 | 72% |
| Underwriting expenses | $26,000,000 | 26% |
| Combined ratio | — | 98% |
| Underwriting profit | $2,000,000 | 2% |
When combined ratio is 105
Losses $76 million, expenses $26 million, premium $100 million:
$76,000,000 ÷ $100,000,000 = 76% loss ratio
76% + 26% = 105% combined ratio
$100,000,000 − $76,000,000 − $26,000,000 = −$2,000,000 underwriting loss
(105% − 100%) × $100,000,000 = −$2,000,000
When combined ratio is 92
Losses $66 million, expenses $26 million, premium $100 million:
$66,000,000 ÷ $100,000,000 = 66% loss ratio
66% + 26% = 92% combined ratio
$100,000,000 − $66,000,000 − $26,000,000 = $8,000,000 underwriting profit
(100% − 92%) × $100,000,000 = $8,000,000
Sustained results near 92 on a large commercial book tend to draw capacity and competition over time — the soft side of the cycle, where new money enters and rates drift down.
Why a carrier can lose on underwriting and still profit
Premiums often arrive before large claims are paid. That timing creates float: investable assets backed by claim liabilities not yet due. Combined ratio ignores float earnings.
Take combined ratio 102 on $100 million premium with expenses still $26 million. Losses must be $76 million:
$76,000,000 ÷ $100,000,000 = 76%; 76% + 26% = 102%
Underwriting loss: $100,000,000 − $76,000,000 − $26,000,000 = −$2,000,000
Add pretax investment income allocated to the segment—$6 million for illustration:
−$2,000,000 + $6,000,000 = +$4,000,000 pre-tax contribution (simplified)
The carrier lost two million on underwriting at 102 and still added four million before tax once investments are counted.
Float is owed to policyholders as claims. Weak yields and rising loss trend make 102 harsh; “above 100” signals underwriting stress, not automatic insolvency.
Why 100 is not the whole story
Prior-year reserve development
Reserve revisions on old accident years flow through current incurred losses. Favorable development lowers today’s loss ratio and combined ratio even when current-year pricing is thin. Unfavorable development inflates the ratio because prior reserves were low. A calendar-year 98 blended with releases is not the same as a 98 on current accident-year loss alone.
Catastrophe and weather
A quiet catastrophe year depresses the loss ratio; one regional event can push calendar-year combined ratio above 100. Carriers manage accumulation and probable maximum loss accordingly—see catastrophe portfolio management. Cat-heavy years often precede tighter terms and rate follow-through with a lag.
Reinsurance and expense optics
Quota-share ceding commission can improve the net expense ratio while gross combined ratio tells a different story. Excess-of-loss and aggregate treaties change how spikes hit the net ratio. Treaty mechanics appear in reinsurance treaty structures and the reinsurance treaty guide; why carriers cede at all is laid out in reinsurance fundamentals. January reinsurance renewals reprice expected net combined ratio for the year ahead—capacity and attachments feed primary pricing with delay, as in notes on the global reinsurance market and January renewal.
Calendar-year vs accident-year
Calendar-year combined ratio uses all losses and underwriting expenses recognized in the calendar period: claim payments on old and new policies, reserve changes on prior accident years (development), and expenses booked this year.
Accident-year combined ratio assigns losses to the year the accident occurred—often shown at a fixed development age (for example, 2026 accident year at 12 months). Expenses are allocated to that cohort or shown separately by filing convention.
Worked contrast on the same carrier:
Calendar-year 2026 incurred losses might include $72 million on $100 million premium, but $8 million of that is favorable development on 2023–2025 reserves. Strip development and current accident-year loss is $80 million on the same premium:
$80,000,000 ÷ $100,000,000 = 80% loss ratio
With a 26% expense ratio, accident-year combined ratio = 80% + 26% = 106% while calendar-year combined ratio with development remains 98%.
Analysts lean on accident-year combined ratio for cycle reads because calendar-year mixes history with current underwriting. A headline 98 with accident-year 106 means forward pricing may still be catching up to loss trend.
Calendar-year is the statutory and GAAP reporting window. Accident-year is the diagnostic. At renewal, ask which view supports the rate change.
What the number says about your renewal
Combined ratio is segment or entity level; your policy is one row on the book. Persistent combined ratios above 100 on your line and region still signal hard-market pressure: underwriters push rate, deductibles, sublimits, and line size until accident-year underwriting returns toward break-even.
- Sustained 100+ on the segment — Expect continued rate action and loss-history scrutiny; underwriters are repairing margin.
- High 90s calendar-year with accident-year deterioration — Renewals can firm even when last year’s headline looked fine; pricing is forward-looking.
- Low 90s with stable development — Capacity may grow; use the window for retention and structure, not rate alone.
Questions for your broker:
- What combined ratio does the carrier report for this line, gross and net of reinsurance—and calendar-year or accident-year?
- Did catastrophes, large losses, or reserve development move the recent ratio?
- How does our account loss ratio compare to the book—and are we a profitable relationship?
- Did reinsurance renewal change retention or ceding commission in ways that affect our layer?
Carrier math explains why the quote moved; it does not replace your loss forecasts.
FAQ
What does the combined ratio measure?
The combined ratio measures underwriting profit or loss as a percentage of earned premium. It equals incurred losses plus underwriting expenses, divided by earned premium, or equivalently the loss ratio plus the expense ratio. A combined ratio below 100 means underwriting profit; above 100 means underwriting loss before investment income and other non-underwriting items.
What is the difference between the loss ratio and the expense ratio?
The loss ratio is incurred losses divided by earned premium—it captures claim payments and reserve changes for the period. The expense ratio is underwriting expenses divided by earned premium—it captures commissions, acquisition costs, and the cost of running the insurance operation. Both use the same premium denominator; adding them yields the combined ratio.
How do you calculate a combined ratio on $100 million of premium?
On $100 million of earned premium, divide incurred losses by $100 million to get the loss ratio, divide underwriting expenses by $100 million to get the expense ratio, and add the two percentages. Example: $72 million losses (72%) plus $26 million expenses (26%) equals a 98 combined ratio and $2 million underwriting profit ($100 million minus $72 million minus $26 million).
Why can an insurer lose money on underwriting and still report a profit?
Because combined ratio excludes investment income on float. Premiums are collected before many claims are paid, so the carrier invests those funds. A combined ratio above 100 produces an underwriting loss, but investment income and other income can more than offset that loss. Example: a 102 combined ratio on $100 million premium with $76 million losses and $26 million expenses is a $2 million underwriting loss; $6 million of investment income still leaves a positive pre-tax contribution in a simplified view.
What is the difference between a calendar-year and an accident-year combined ratio?
Calendar-year combined ratio includes all losses and expenses recognized in the calendar period, including payments and reserve changes on policies from prior years. Accident-year combined ratio assigns losses to the year the accident occurred, isolating how policies written in that year are performing at a given development age. Calendar-year is the reporting period for earnings; accident-year is preferred for reading current underwriting and cycle direction.
What does the combined ratio tell you about your renewal?
It signals carrier margin pressure on your line, not your individual policy’s pricing formula. Persistent combined ratios above 100 on your segment usually mean continued rate firming and tighter terms until underwriting returns to break-even or better on an accident-year basis. Ask whether the carrier’s headline ratio was distorted by catastrophes, reserve development, or reinsurance, and whether accident-year results support the renewal change you received.