WCRates

Workers' comp premium calculator

Estimate your workers' compensation premium from your state, class code, payroll and experience modification factor — then read exactly what your carrier does to that number before it becomes the figure on your policy.

Rates as of . Algorithm sources retrieved .

Covers the 47 jurisdictions rated on an NCCI class code per $100 of payroll. North Dakota, Ohio, Washington and Wyoming are not included. Each is a monopolistic state fund that sets premium on its own basis rather than on an NCCI class-code rate per $100 of payroll, so there is no comparable figure to average or rank.

$

Gross annual payroll for employees assigned to this classification. Multi-code employers rate each class code separately and add the manual premiums together.

Leave at 1.00 if you are not experience rated or don't know your mod. Your mod is published by your rating bureau, not by your carrier — see how the experience mod is calculated.

Select a state and class code, then enter your payroll to see your estimated premium.

The premium algorithm, step by step

Rating bureaus publish the premium calculation as an ordered list of elements, and the order matters: applying the experience mod after the premium discount, or adding the expense constant on top of a minimum premium, produces a different — and wrong — answer. The table below collapses that list to the eight steps that change what a small employer pays. Two steps are marked calculated here; the other six depend on filings specific to your carrier or your policy.

The eight steps of the workers' compensation premium algorithm, and which of them this calculator computes
StepWhat happens
1. Manual premiumCalculated hereAnnual payroll ÷ 100 × the class code rate, calculated separately for every class code on the policy and then added together.
2. Subject premiumManual premium plus the items that are themselves experience rated — employers' liability increased limits, deductible credits, carrier rate deviations, waiver of subrogation.
3. Experience modificationCalculated hereSubject premium × your bureau-published experience mod. A mod below 1.00 is a credit, above 1.00 a debit. Employers too small to qualify are rated at 1.00.
4. Schedule ratingA carrier-filed credit or debit for risk characteristics an underwriter can see but the mod does not capture — safety programme, housekeeping, management cooperation. Not available in every state.
5. Standard premiumThe subtotal after experience and schedule rating. Premium discount, the expense constant and terrorism/catastrophe charges are deliberately excluded from it.
6. Premium discountA size-graded reduction applied to standard premium, on the reasoning that a larger policy costs proportionally less to issue and service. Small policies get little or none.
7. Expense constantA flat per-policy charge for issuing and auditing the policy. It is not subject to the experience mod or the premium discount — and it is already built into the minimum premium, so it is not added again when the minimum premium becomes the final premium.
8. Minimum premium, terrorism and assessmentsIf everything above lands below your state's minimum premium, you pay the minimum. Terrorism and catastrophe charges are then added per $100 of payroll, followed by any state assessment or surcharge.

A worked example

A restaurant with $260,000 of annual payroll under a single class code carrying a published rate of $2.10 per $100, and a bureau-published experience mod of 0.92:

  1. Manual premium: $260,000 ÷ 100 = 2,600 units of payroll. 2,600 × $2.10 = $5,460.
  2. Modified premium: $5,460 × 0.92 = $5,023. The 0.08 credit is worth $437 a year.
  3. Schedule rating: if the carrier files a 5% credit for a documented safety programme, standard premium becomes $4,772.
  4. Premium discount: at this size the discount is small or zero, so the figure is largely unchanged.
  5. Expense constant: a flat per-policy charge is added — unless the minimum premium has become the final premium, in which case the constant is already inside it and is not added again.
  6. Terrorism, catastrophe and any state assessment are added last, each as a small per-$100-of-payroll or percentage charge.

The rate and mod in this example are illustrative. Use the calculator above with your own state and class code for a rate drawn from the published filings.

What actually moves your premium

Classification, first and by a wide margin. The spread between class codes within one state is far larger than the spread for one class code across states — clerical work and roofing can differ by more than an order of magnitude per $100 of payroll. A misassigned code is the single most expensive administrative error on a comp policy, in either direction: an audit that reclassifies you upward is retroactive.

Then the experience mod. It multiplies the whole subject premium, so a 0.15 movement in the mod is a 15% movement in premium regardless of size. Claim frequency moves the mod more than claim severity, because the primary portion of each loss is fully weighted while the excess portion is discounted — several small claims damage a mod more than one large one of the same total value.

Then the state. Loss costs are filed per state and refiled most years; a state with several consecutive decreases has compounded them. See the state rate hubs for current filings, or compare two states side by side.

Carrier choice, last but not trivially. In loss-cost states the published loss cost is only the expected claim cost; each carrier files its own loss cost multiplier on top. Two carriers quoting the same class code in the same state can differ substantially on the multiplier alone, which is why a rate estimate never substitutes for shopping the risk.

Sources for the algorithm

The ordering above is taken from the rating bureaus' own published premium algorithms rather than from secondary summaries. All four were read on .

The rates themselves — where each state's figure comes from, how the per-state index is built and how often it is refreshed — are documented separately on the rate methodology page.

Frequently Asked Questions

Keep going