Workers Compensation Premium Calculator

Work out workers compensation premium instantly with clear inputs, formula shown and shareable results.

About Workers Compensation Premium Calculator

Workers compensation premium is payroll divided by 100 times a class rate, then multiplied by an experience modification factor that compares your claims history with the class average. A modifier below 1.0 is a credit, above 1.0 a debit — which is how safety performance translates directly into premium.

Formulas

Manual premium

Manual premium = Payroll / 100 x Class rate

Premium

Premium = Manual premium x Experience modifier x (1 - Schedule credit %)

Worked example

With the default values below, Workers Compensation Premium Calculator returns Annual workers compensation premium of $1,409,256.00. Change any input above and every figure here is recalculated in your browser.

Inputs used

Annual payroll: 90,000,000
Rate per 100 of payroll: 1.85
Experience modification factor: 0.92
Schedule rating credit: 8

Results

Annual workers compensation premium: $1,409,256.00
Manual premium before modification: $1,665,000.00
Effect of the experience modifier: -$133,200.00
Effective rate per 100 of payroll: 1.5658

Step by step

1Values used
2Manual premium
3Premium
4Annual workers compensation premium= 1,409,256.00
5Manual premium before modification= 1,665,000.00
6Effect of the experience modifier= -133,200.00
7Effective rate per 100 of payroll= 1.5658

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or fees or charges into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Indicative estimate only. Fees, entitlements, limits and formulas vary by jurisdiction, statute, policy wording and the facts of the case. This is not legal, tax, insurance or financial advice — confirm with a qualified professional or the relevant authority.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Indicative estimate only. Fees, entitlements, limits and formulas vary by jurisdiction, statute, policy wording and the facts of the case. This is not legal, tax, insurance or financial advice — confirm with a qualified professional or the relevant authority.

Frequently Asked Questions

How is the experience modifier calculated?

From your actual losses over a three-year window compared with expected losses for your class and size, with claim frequency weighted more heavily than severity.

Why does frequency matter more than severity?

Because frequency is more predictive of future losses and more controllable. Rating formulas deliberately penalise many small claims.