How is Illinois workers' comp premium calculated?

Workers' comp premium uses the same formula nationwide: (annual payroll ÷ 100) × the class base rate × your experience modifier. The class base rate is a dollar amount per $100 of payroll that depends on how risky the job is, so clerical work costs cents per $100 while roofing can cost $15 or more per $100. Carriers then add expense constants and any state assessments.

Does Illinois have a state workers' comp fund?

No. Unlike states such as Ohio or Washington, Illinois does not run a competitive state insurance fund. Employers buy workers' compensation from private insurance carriers on the open market, or, for hard-to-place high-risk businesses, through the NCCI assigned-risk pool. There is no state-fund discount to apply.

What is an experience modifier (EMR)?

The experience modification rate compares your company's actual loss history to the expected losses for businesses of your size and class. A factor of 1.00 is average. Below 1.00 means a better-than-average safety record and a premium discount; above 1.00 means worse claims experience and a surcharge. New employers without loss history start at 1.00.

Where do I find my Illinois class code base rate?

Your job classifications follow the NCCI-style four-digit class codes, and the per-$100 base rate is filed and published for Illinois. Your insurance agent or carrier will tell you the exact rate for each code on your policy. The sample rates in this tool are representative only and should not be treated as a quote.

Is this an official Illinois workers' comp quote?

No. This is an educational estimate. Actual premiums depend on your carrier's filed rates, your specific experience modifier, expense constants, schedule credits or debits, and state assessments. For a binding number, get a quote from a licensed Illinois insurance agent and verify rules with the Illinois Workers' Compensation Commission at iwcc.il.gov.

Illinois Workers' Compensation Premium Calculator

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Workers’ compensation is mandatory for almost every Illinois employer, and the cost is driven by three numbers: your payroll, the risk class of the work, and your safety track record. This calculator applies the standard manual-premium formula used by every carrier so you can estimate your annual Illinois workers’ comp cost before you call an agent.

How it works

Workers’ comp premium is built up in three steps:

Manual premium = (Annual payroll ÷ 100) × Class base rate Modified premium = Manual premium × Experience modifier (EMR) Final premium = Modified premium × (1 + surcharges)

The class base rate is a dollar figure per $100 of payroll. Low-risk clerical work might be $0.14 per $100, while roofing can exceed $16 per $100 because the injury risk — and average claim cost — is far higher.

The Illinois specifics

No state fund. Illinois employers buy comp from private carriers or the NCCI assigned-risk pool. There is no competitive state fund and therefore no state-fund discount.
Class codes drive the rate. Each job classification has its own filed base rate. Mixing low-risk and high-risk work means each payroll bucket is rated separately.
Experience modifier. Once you have a few years of history, your EMR rewards safety with a discount or penalizes a poor claims record with a surcharge.

Worked example

A restaurant (class 9079, rate $1.40 per $100) with $60,000 of payroll and a new-employer EMR of 1.00:

Payroll units = 60,000 ÷ 100 = 600
Manual premium = 600 × $1.40 = $840
Modified premium = $840 × 1.00 = $840/year

Note: This is an estimate, not a quote. Real premiums add expense constants, schedule credits/debits, and state assessments, and depend on your carrier’s filed rates and your actual experience modifier. Verify with a licensed Illinois agent and iwcc.il.gov.