Workers' Comp Premium Calculator — Free, With Audit True-Up

What is your workers' comp premium really made of?

Enter the payroll and rate per $100 for each class code from your quote or declarations page, plus your experience mod. The tool rebuilds the premium line by line, shows what each 0.10 of mod is worth, and — if you add actual payroll — what a final audit will add or return. Rates are yours; nothing is looked up or guessed.

Nothing is uploaded. Your payroll is read in this browser and never leaves your device.

1. Payroll by class code

Class / label	Estimated payroll ($)	Rate per $100	Overtime wages in payroll ($)	Actual payroll at audit ($, optional)	Remove

Put uninsured subcontractors in their own row at the rate and amount your carrier charges for them. Overtime multiplier is assumed to be 1.5 unless you change it below.

2. Modifiers and charges

Experience mod (1.00 = average)

Schedule credit (−) or debit (+), %

Premium discount, %

Surcharges and assessments, % of premium

Expense constant ($)

Other flat fees ($)

Overtime multiplier

3. What if the same payroll sat in a different class? (optional)

Payroll ($)

Current rate per $100

Other rate per $100

Enter payroll and a rate for at least one class, then click Calculate premium.

What this does not cover

Not insurance, legal, tax, or financial advice. Your carrier's quote and audit control.
No rate or class-code lookup. You supply the rates; state rating bureaus and carriers publish them.
No state-specific rule engine. Overtime exclusion, premium discount tables, owner-officer rules, deductible programs and minimum premiums differ by state and carrier and are not modeled beyond the fields above.
No experience-mod calculation. You enter the mod; the tool does not recompute it from claims.

Common questions

How is workers' compensation premium calculated?

Premium is payroll divided by 100, times the rate for each class code, summed across classes to get manual premium. That is multiplied by your experience modification, adjusted by any schedule credit or debit, reduced by any premium discount, and then flat charges such as an expense constant are added.

What is an experience modification rate?

The experience mod compares your claims history over a recent multi-year window with what is expected for a business of your size and class. A mod of 1.00 is average, above 1.00 raises your premium and below 1.00 lowers it. Your rating bureau or carrier publishes the worksheet, and errors on it are worth disputing.

Is overtime pay included in workers' comp payroll?

In most states only the straight-time part of overtime is premium basis. At time-and-a-half, one third of each overtime dollar is the premium portion and is excluded, but only if your payroll records show overtime separately. Check your own state and carrier rules.

Why did my workers' comp audit bill me extra?

The policy is written on estimated payroll. At the end of the term the carrier audits actual payroll, and any difference is charged or returned at the same rates. Growth, more overtime, or uninsured subcontractors added to your payroll are the usual causes of an additional premium.

Is this an insurance quote?

No. It does the arithmetic on rates you type in from your own quote or policy. It does not look up class codes or rates, it is not insurance or legal advice, and your carrier's figures control.