How is workers' comp premium calculated?

The core formula is payroll divided by 100, multiplied by the class-code rate, multiplied by the experience modifier. Premium equals (payroll / 100) times rate times EMR. The rate is per 100 dollars of payroll because that is the industry convention.

What is an experience modifier (EMR)?

The EMR compares your claims history to other employers in your class. An EMR of 1.00 is exactly average, below 1.00 means a better-than-average safety record and a discount, and above 1.00 means worse claims and a surcharge.

Where do class-code rates come from?

Each job type has a National Council on Compensation Insurance (NCCI) classification code with an assigned base rate reflecting its injury risk. Clerical work has a very low rate while roofing or framing has a high one. Your insurer lists the rate per code on your policy.

Is Colorado a monopolistic state for workers' comp?

No. Colorado has a competitive market. Pinnacol Assurance is the large state-chartered carrier, but private insurers also write policies. Employers can shop rates, unlike the few monopolistic states that require a state fund.

Is this my exact premium?

No. This is a manual-premium estimate. Real policies also apply schedule credits, expense constants, terrorism charges, and minimum premiums, and large employers may use loss-sensitive plans. Use the figure for budgeting and confirm with a licensed agent.

Colorado Workers' Compensation Premium Calculator

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A Colorado employer’s workers’ comp cost comes down to three numbers: the class-code rate, the payroll, and the experience modifier. This tool applies the standard premium formula so you can budget your annual cost.

How it works

Rates are quoted per $100 of payroll. The manual premium is multiplied by your experience modifier (EMR):

manual premium  = (annual payroll / 100) × class-code rate
estimated premium = manual premium × EMR

An EMR of 1.00 is average; 0.85 is a 15% safety discount; 1.20 is a 20% surcharge for above-average claims.

Example

A $500,000 payroll at a $2.50 rate gives a manual premium of (500000 / 100) × 2.50 = $12,500. With a 0.90 EMR the estimated premium is 12500 × 0.90 = $11,250.

Notes

This is a manual-premium estimate. Real policies add schedule credits, expense constants, and minimum premiums, and large employers may use loss-sensitive plans. Colorado has a competitive market — Pinnacol plus private carriers — so shop rates and confirm with a licensed agent.