How is a workers' comp premium calculated?

The standard formula is payroll divided by 100, multiplied by the class code base rate, multiplied by your experience modifier. The result is the annual manual premium before any schedule credits, discounts, or fixed expense constants.

What is a class code base rate?

Each job type has a classification code (set by NCCI) with a rate expressed per 100 dollars of payroll. Office work might be under 0.30 dollars while roofing can exceed 15 dollars, reflecting the injury risk of the occupation.

What is an experience modifier?

The experience modifier (mod) adjusts premium up or down based on your past claims history versus similar employers. A mod of 1.00 is average, below 1.00 earns a credit for good safety, and above 1.00 adds a surcharge for higher losses.

Is Oklahoma a monopolistic workers' comp state?

No. Oklahoma has a competitive market where employers buy coverage from private carriers or the state-affiliated CompSource Mutual, and qualifying employers may self-insure. Rates and credits therefore vary by carrier within the same class code.

What does this estimate leave out?

It computes the manual premium only. Actual policies add an expense constant, may apply premium discounts for size, schedule credits or debits, terrorism and assessment charges, and a minimum premium, so your quoted price can differ from this figure.

Oklahoma Workers' Compensation Premium Calculator

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Workers’ compensation premium in Oklahoma follows a standard, transparent formula based on payroll, the job’s risk class, and your claims history. This calculator applies that formula so you can budget the annual cost of covering each class of worker.

How it works

The manual premium is built from three numbers:

Payroll per 100. Premium is rated per $100 of payroll, so divide annual payroll by 100.
Class code base rate. Each classification code has a rate per $100 reflecting its injury risk — low for clerical, high for construction.
Experience modifier. Multiply by your experience mod, where 1.00 is average, below 1.00 is a credit, and above 1.00 is a surcharge.

The formula is premium = (payroll ÷ 100) × rate × mod. An optional fixed expense constant can be added to match the way real policies are priced.

Tips and example

Suppose you have $500,000 of payroll in a class code rated at $2.50 per $100, with an experience mod of 0.95. The estimate is (500,000 ÷ 100) × 2.50 × 0.95 = 5,000 × 2.50 × 0.95 = $11,875 per year.

Oklahoma is a competitive-market state — you can buy from private carriers or CompSource Mutual — so rates and credits differ by insurer for the same class code. Real quotes also add expense constants, premium discounts, and assessments not modelled here.