Expected Claim Frequency Calculator
Claim frequency is how often claims occur per unit of risk: claims divided by exposures. It is the first half of the pure premium, alongside claim severity. This calculator works out the frequency from observed claims and exposures, then projects the expected number of claims for a portfolio of any size. Use it to set pricing assumptions and to test how frequency scales.
Claim frequency formula
Claim frequency = number of claims / exposure units
Frequency percent = claim frequency * 100
Expected claims = claim frequency * projected exposures
Frequency is dimensionless per exposure. Multiplying it by any exposure count gives the expected number of claims for that book under the same conditions.
Reading the result
- Claim frequency is the average number of claims each exposure unit generates.
- The percent form is convenient when frequency is below one claim per exposure.
- Expected claims scales the frequency to your projected portfolio.
- Adjust for trend and credibility before using the figure in pricing.
Claim frequency: frequently asked questions
What is claim frequency?
Claim frequency is the number of claims divided by the number of exposure units, such as policies or vehicle-years. It measures how often claims occur per unit of risk. Together with claim severity (average cost per claim), it forms the pure premium that underlies risk-based pricing.
What is an exposure unit?
An exposure unit is the standard measure of the amount of risk insured, for example one car insured for one year, or one insured house-year. Frequency is expressed per exposure so it can be compared across portfolios of different sizes. Enter the number of exposure units that produced the claims.
How do I find the expected number of claims?
Multiply the claim frequency by the number of exposures you want to project. If frequency is 0.05 claims per exposure and you have 10,000 exposures, the expected number of claims is 500. This calculator returns both the frequency and the expected claim count.
Is past frequency a reliable predictor?
Historical frequency is the usual starting point, but it should be adjusted for trends, changes in the book, and the credibility of the data. A small sample produces a noisy estimate. Actuaries often blend observed frequency with a wider benchmark to improve reliability.
Sources and method
- Claim frequency is the standard actuarial ratio of claims to exposures; expected claims is frequency times projected exposures. All inputs are user-editable; no figure is hardcoded.
- National Association of Insurance Commissioners: NAIC for ratemaking concepts.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.