Workers' comp premium calculator

How workers' compensation premiums are calculated

Workers' compensation insurance premiums are set by a formula, not by negotiation. Every U.S. state (except the five monopoly-fund states) uses class codes developed by the National Council on Compensation Insurance (NCCI) to group employees by the risk level of their work. The formula is:

Standard premium = (Annual payroll ÷ $100) × Base rate
Mod-adjusted premium = Standard premium × Experience Modification Rate (EMR)

NCCI class codes

Each class code reflects the statistical claim frequency and severity for that type of work. A clerical office employee (code 8810) carries a base rate under $0.30 per $100 of payroll because desk workers rarely suffer serious injuries. A roofer (code 5160) carries a base rate over $20.00 per $100 because falls are frequent and severe. The carrier multiplies that rate by your payroll to set the standard premium before any modifications.

Experience modification rate (EMR / X-Mod)

Once your business has at least three years of claims history, NCCI calculates an experience modification rate (EMR) that compares your actual losses to the expected losses for your class and size. An EMR of 1.00 means your claims are average. Below 1.00 means fewer or smaller claims than expected — your premium is discounted. Above 1.00 means more or larger claims — your premium carries a surcharge. A new employer without an EMR defaults to 1.00.

Why rates vary by state

NCCI files manual rates separately in each state where it operates, and state insurance departments approve them. Rates for the same class code can differ by 30–50% across states because loss costs, medical costs, and state benefit levels all vary. California, North Dakota, Ohio, Washington, and Wyoming operate state monopoly funds — employers in those states must buy coverage from the state fund, not from private carriers, and NCCI rates do not apply.

Schedule credits and debits

Beyond the EMR, carriers can apply schedule credits (for safety programs, loss-control participation, premium size) or debits (for adverse risk characteristics). These modifications are negotiated and are not shown in this calculator. The estimate above reflects the manual rate and EMR only.

Worked example

A landscaping company in Texas has $800,000 in annual payroll and an EMR of0.87 from three years of below-average claims.

• NCCI class code 0042 (landscaping) — national average base rate: $5.50 per $100
• Standard premium: (800,000 ÷ 100) × $5.50 = $44,000
• Mod-adjusted premium: $44,000 × 0.87 = $38,280
• EMR savings vs. neutral (1.00): $5,720 per year

If the same company had an EMR of 1.15 from a bad claims year, their premium would rise to $44,000 × 1.15 = $50,600 — a $12,320 surcharge. A single preventable injury can push an EMR above 1.0 for three years.

Assumptions and limitations

• Rates shown are approximate NCCI national averages. Your actual base rate depends on the specific state filing in effect for your policy year.
• CA, ND, OH, WA, and WY use state monopoly funds with their own rate schedules. This calculator uses NCCI average rates as a rough reference for those states only.
• Schedule credits, tier discounts, loss-sensitive plans, and large-deductible programs are not reflected. Actual carrier quotes may differ significantly.
• This calculator does not determine whether an employee is correctly classified. Payroll audits can reclassify employees and change premiums retroactively.
• This is not an insurance quote. Contact a licensed workers' compensation broker for a binding rate.

Frequently asked questions

What is an experience modification rate (EMR)?

An EMR (also called X-Mod) is a multiplier that adjusts your workers' comp premium based on your actual claims history versus the statistical average for your class and payroll size. NCCI calculates it annually using a rolling three-year window of loss data. A neutral EMR is 1.00; good safety records produce an EMR below 1.00; above-average claims produce an EMR above 1.00.

How do I find my NCCI class code?

Your class code appears on your workers' compensation policy declarations page, usually in the schedule of operations. If you're unsure, a licensed WC broker or your state's workers' compensation rating bureau can help classify your employees correctly.

Can I use two class codes?

Yes — if your employees do materially different types of work, you can assign different class codes to different payroll amounts. The calculator's "Add a second class code" option handles this. Each code's premium is calculated separately and then summed before the EMR is applied.

What are the monopoly states?

California, North Dakota, Ohio, Washington, and Wyoming require employers to purchase workers' comp coverage exclusively from a state fund rather than a private insurer. NCCI rates and class codes don't apply; contact each state's fund directly for a rate quote.

How can I lower my workers' comp premium?

The most direct lever is reducing your EMR through better claims management: prompt return-to-work programs, a written safety plan, OSHA 300 log discipline, and working with your carrier's loss-control team. A one-point EMR improvement on a $50,000 standard premium saves $50,000 per year and persists for three policy years.