Who this is for: independent commercial-lines P&C insurance brokers.
The pitch in one line: upload your rater spreadsheet → get a fillable web form your producers can use today. No re-typing, no rebuild. Your formulas, your rates, your lookup tables — translated as-is.
The workbook you've been carrying around since 2014
Every commercial broker has it. We've seen ours called AcmeRater_v17_FINAL_final2.xlsx. It looks like this:
| Tab | What it does |
|---|---|
| Inputs | Named insured, state, SIC class, revenue, payroll, TIV, EMR, years in business, loss ratio, GL limit, umbrella limit, schedule credits |
| GL Rates | VLOOKUP of class → base rate per $1k revenue |
| ILF Table | Increased Limit Factors by per-occurrence limit |
| WC Rates | Per-$100-payroll rate by class |
| State Tax | Premium tax + stamping fee by state |
| GL Calc | =annual_revenue / 1000 * base_rate * ilf * (1 - sched_credit/100) * (1 + exp_mod_load) |
| Property Calc | TIV / 100 × rate × credit factors × CAT load |
| WC Calc | Payroll × rate × EMR × (1 - schedule credit) × (1 - size discount) + expense constant |
| Umbrella Calc | GL_net × factor (lookup of umbrella limit) |
| Subtotal | sum of four lines |
| Taxes & Fees | subtotal × state_tax + subtotal × 0.0015 |
| Total Program | round(subtotal + taxes, 2) |
| Commission | total × commission_pct |
| Net to Carrier | total - commission |
| ... | (37 more tabs for binder, fee schedule, ACORD field mapping, etc.) |
You email it to a producer. They duplicate the file. They fill in the inputs. They send it back. You can never find which version is the latest. Last quarter you lost a $42K commission because the producer used the old rate table.
The CalcForms version
The fastest path: drop the workbook into Claude
You don't need to retype anything. Drag your AcmeRater_v17_FINAL_final2.xlsx into a Claude chat that has the CalcForms connector enabled, and say:
Build this as a CalcForms form. Inputs tab fields become form inputs, the calc tabs become calculations, and the rate / ILF / state tax tabs become lookup tables.
Claude reads every sheet: it identifies which cells are inputs (no formulas, just values from the user), which are intermediates (formulas referencing other cells), and which are lookup tables (named ranges or VLOOKUP targets). It translates your Excel formulas — IF, VLOOKUP, ROUND, MIN/MAX, nested conditionals — into CalcForms expressions, calls create_form for you, and the builder UI appears in the chat. You spot-check the numbers against the original workbook (paste the same test inputs, compare totals). Fix any wrong translations by saying "the WC size discount should kick in at $5M payroll not $1M." Deploy.
Time from "drag the .xlsx" to "deployed URL": 15-20 minutes, most of which is the spot-check.
Or describe it from scratch
If you don't have an existing workbook (or want to clean-slate the rates):
Build me a commercial GL/Property/WC/Umbrella rater. Class-based GL rates: Office $1.10, Retail $2.20, Light Manufacturing $4.25, Contractor $5.75, Heavy Manufacturing $6.50. ILF: 500K=0.85, 1M=1.00, 2M=1.35, 5M=1.75. WC rates: Office $0.35, Retail $1.25, Light Manufacturing $2.20, Contractor $5.20. State tax: TX 4.85%, CA 3%, NY 3.6%, FL 5%. Add experience mod load for loss ratios over 100% (+5%) and over 60% (+2%). Schedule credits on GL and WC, capped at ±25%. Umbrella factor of GL net: 5M=0.45, 10M=0.70, 25M=1.10. Include broker commission percentage.
6 minutes later you have:
You type a test quote — $28.5M revenue, Light Manufacturing, TX, 1M GL limit — and the result panel updates in 300ms:
- GL Manual Premium: $121,125
- WC Net: $218,914
- Property Net: $13,453
- Umbrella Net: $50,037
- Subtotal: $403,529
- Taxes & Stamping: $19,680
- Total Program: $413,277
- Broker Commission (15%): $61,991
- Net to Carrier: $351,285
If a number's off, you say "the Manufacturing rate should be $4.10 not $4.25" and Claude updates the lookup table. Numbers re-flow instantly. You ship it: "deploy this". Now it's live at forms.badabingapp.cc/f/acme-commercial-rater.
You email the URL to every producer in the firm. Or send invites: "send invite to john@acmebrokerage.com" — John gets a magic link, fills it in, his progress auto-saves between sessions. When he submits, you see every input + every calc in your dashboard.
The outcome
| Excel workbook | CalcForms | |
|---|---|---|
| Time to build a new rater | 2-3 weeks (version control hell) | 6 minutes |
| Time to update rates across firm | "email everyone the new file" → some never get it | One conversation with Claude |
| Producer fills out a quote in | 15-20 min (open file, find tab, type, save, email) | 4-6 min (browser, type, submit) |
| You can audit what they entered | Only if they sent the file back | Always — full submission row in dashboard |
| Re-quote with different limits | Re-open file, change inputs, re-save | "Run scenario on submission #42 with GL limit 5M instead of 1M" |
| Send to a client for self-serve | Never (the file is too dangerous to share) | One URL |
The wedge isn't replacing your AMS. It's killing the email-the-spreadsheet-around workflow that wastes 8 hours of producer time a week.
Try it
Live working example (the one in the screenshot above):
forms.badabingapp.cc/f/commercial-underwriting
That's our reference Acme-style underwriter. Fork it, change the rates to your book, deploy in an hour.
Or just open Claude with the CalcForms connector and ask it to build yours from scratch. The fastest broker we've tested went from "I have a workbook" to "I have a deployed URL my producers are using" in 47 minutes — and 30 of that was finding the right rate tabs in the original Excel.