Workers’ Comp Cost Calculator
Estimate annual Workers’ Comp premium from your state’s actually-filed loss cost — cited to its SERFF tracking number — multiplied by your payroll and a typical carrier Loss Cost Multiplier (LCM). No blended averages, no invented numbers.
How Workers’ Comp premium is actually calculated
Workers’ Comp pricing in the US runs through a four-step chain that almost no consumer site explains transparently. Understanding it is the difference between trusting the number a calculator gives you and just hoping it’s right.
- The bureau (NCCI or your state rate bureau) files an advisory loss cost with your state Department of Insurance for every WC class code. The loss cost is the pure-loss component — what carriers expect to pay out in claims per $100 of payroll for that class, before any expenses or profit. Bureaus refile annually; the filing is public and has a SERFF tracking number you can verify directly with the state DOI.
- Each carrier files its own Loss Cost Multiplier (LCM) with the state. The LCM converts loss cost → final rate by adding in the carrier’s expenses, profit margin, and acquisition costs. Voluntary-market LCMs typically run 1.20-1.50 for small-business carriers (Hartford, Travelers, Liberty, AmTrust); assigned-risk pools run higher.
- Your experience modifier (mod) adjusts the result up or down based on YOUR loss history vs. industry expectation. New businesses start at 1.00; businesses with claim-free track records earn mods below 1.00 (lower premium); businesses with worse-than-expected losses pay mods above 1.00.
- Schedule rating + state surcharges finish the math — carriers may apply credits/debits for risk-control factors (return-to-work programs, safety committees) and state-mandated surcharges (terrorism, second-injury fund, etc.) are added last.
Our calculator returns the result of steps 1-2 (loss cost × payroll × LCM range) because steps 3-4 are carrier-and-history-specific. The number we show is the actuarial floor a real quote starts from.
A worked example: $500K-payroll carpentry shop in Colorado
Real numbers from the captured Colorado 5645 filing (NCCI-134620513, eff 1/1/2026):
- Class code 5645 (Carpentry — Residential Dwellings ≤ 3 Stories), Colorado, 1/1/2026 filing
- Filed loss cost: $1.993 per $100 payroll
- Annual payroll: $500,000
- Loss cost × payroll: $1.993 × ($500,000 ÷ 100) = $9,965 expected loss
- Apply LCM 1.20 (low-end carrier): $9,965 × 1.20 = $11,958 estimated annual premium
- Apply LCM 1.50 (higher-LCM carrier): $9,965 × 1.50 = $14,948 estimated annual premium
Range: $11,958–$14,948 for this exact business profile, before experience modifier and schedule credits/debits. Cited to NCCI-134620513 on the Colorado DORA Division of Insurance public filing.
Why filed rates beat “national average” calculators
Most online WC cost tools return a blended national average from a vague source ("according to industry data"). The problem: there is no national WC rate. WC is governed state-by-state. NCCI files different loss costs for the same class code in every state it services, and 8 states use independent bureaus (WCIRB CA, NYCIRB NY, NJCRIB, PCRB PA, WCRB WI, ICRB IN, NCRB NC, MA WCRIBMA) with their own filings entirely. Averaging across all that is a category error.
A filed-rate calculator anchors the number to the specific regulatory filing that applies in your state — the same number a carrier’s actuary uses as the starting point of your quote. Cited to SERFF means it’s auditable. The numbers on this page can be verified directly with your state DOI in under five minutes.
FAQ
How is Workers’ Comp premium calculated?
Premium = (Filed Loss Cost ÷ 100 × Payroll) × the carrier’s Loss Cost Multiplier (LCM), adjusted for experience modifier and schedule credits/debits. This calculator uses your state’s actual filed loss cost, cited to its SERFF tracking number.
What is a Workers’ Comp class code?
A 3-4 digit code (NCCI or your state bureau) that classifies your type of work and sets your base rate. Examples: 8810 = clerical office, 5645 = residential carpentry, 9079 = restaurant, 7219 = trucking. NCCI publishes over 600 codes; bureau states maintain their own variants.
What is a Loss Cost Multiplier (LCM)?
The factor a carrier applies to the bureau’s loss cost to set its final rate. LCM covers expenses, profit, acquisition costs, and the carrier’s margin. Two carriers can charge different premiums for the same class code in the same state because they file different LCMs. Voluntary-market LCMs typically run 1.20-1.50 for small-business carriers.
Where does the loss-cost data come from?
State Department of Insurance public rate filings — NCCI advisory loss cost filings for the 38 NCCI states + the independent bureau filings (WCIRB CA, NYCIRB NY, NJCRIB, PCRB PA, etc.) for the other 8. Every number on this calculator carries the SERFF tracking number of its source filing so it can be independently verified. Browse all our captured filings on the rate-changes tracker.
Is this calculator an exact quote?
No — it’s a filed-rate-based estimate. Your actual premium depends on which carrier writes the policy, your experience modifier (claims history), any schedule credits or debits the underwriter applies, and state-specific surcharges (terrorism, second-injury fund, etc.). For a real quote, work with a licensed agent in your state. This tool gets you the floor; a real quote refines from there.
Embed this calculator on your site
Brokers, agents, payroll providers, HR + finance blogs: drop this calculator on your site. Copy-paste — no API, no JS deps. We host + maintain; you keep the visitor on your page with our backlink as attribution.
<iframe src="https://www.getbusinesscoverage.com/embed/wc-cost-calculator"
width="100%" height="680" frameborder="0" loading="lazy"
title="Workers' Comp Cost Calculator — Get Business Coverage"></iframe>
<p><a href="https://www.getbusinesscoverage.com/tools/wc-cost-calculator">
Workers' Comp Cost Calculator by Get Business Coverage</a></p>
Preview the embed · Email press@getbusinesscoverage.com if you want a custom-themed version.
Related
The calculator math (transparent)
The math behind every estimate:
Annual Premium = (Filed Loss Cost × Payroll ÷ 100) × Carrier LCM
- Filed Loss Cost = the per-$100-payroll loss cost the bureau (NCCI / state) filed with your state DOI for your specific class code. This is the regulatory-floor pure-loss component.
- Carrier LCM = the Loss Cost Multiplier each carrier files separately with the state DOI. LCM converts loss cost → final rate. Typical voluntary-market LCM is 1.20–1.50 for small-business carriers (Hartford, Travelers, Liberty, AmTrust); higher in assigned-risk markets.
- The range we return is loss-cost × payroll × LCM-low to LCM-high. Your actual quote depends on which carrier wins your business and what experience modifier (mod) + schedule credits/debits they apply.
Why this matters: most online “WC cost calculators” return blended national averages with no source. Ours is anchored to the specific filing a regulator approved for your state — the number a carrier’s actuary would use as their starting point. Cited to SERFF means it’s auditable.
Data scope (transparent)
v1 of this calculator returns estimates for the class × state combinations we’ve captured from public state DOI filings. Coverage grows as the rate-changes tracker expands — today the tracker holds 48 bureau-wide filings; class-level breakouts are being added on a 5-10/week cadence. Combinations we don’t yet have show a clear “no filed data yet” message rather than a fabricated number.