Actuarium

Loss Trend Forecaster

Fit exponential/linear trend lines to historical frequency, severity, or pure premium and project forward with confidence bands.

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Holt level smoothing (α)0.40
Holt trend smoothing (β)0.20

Projection: Holt vs. log-linear trend

Forecast periodHolt linear trendLog-linear fit
Year +112,312,31612,596,078
Year +212,839,33013,302,973
Year +313,366,34414,049,540

Log-linear annual growth: 5.61%  |  R²: 0.996

Rate vs. trend

QuantityValue
Loss trend factor1.124
Premium trend factor1.040
Rate factor1.040
Projected loss ratio67.5%
Combined ratio
104.5%

Assumptions & limitations
  • Holt's method requires at least 2 data points to initialize level/trend and assumes an additive, non-seasonal linear trend.
  • The log-linear fit assumes constant multiplicative (exponential) annual growth; R² close to 1 indicates a good exponential trend fit.
  • Rate-vs-trend and combined-ratio calculations assume trend/rate changes are geometric (compounded) and apply uniformly across the projection years.
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