Auto Loan Calculator for Dealers

The form your customers fill out

A live calculator, not a static quote request. Your customer enters their details and watches the number update on the spot, which is what turns a browser into a booked job.

What it calculates

Shows the live monthly car payment as the shopper adjusts price, trade-in, down payment and term
Keeps your real APR-by-credit-tier rate table, sales tax rules and dealer fee logic from your F&I spreadsheet
Captures each shopper as a pre-qualified lead with vehicle, trade equity and target payment already calculated
Update rate tiers, manufacturer incentives or doc fees later just by asking Claude
Backtest against booked deals so quoted payments line up with what your lenders actually approve

Why it closes more deals

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A live number closes deals

Customers who see a real estimate the second they enter their details are far likelier to book than ones told to call for a quote. The number is the hook.

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Runs your most complex spreadsheet

Multi-tab workbooks, lookup tables, tiered rates, conditional line items, the lot. If the math runs in Excel, CalcForms runs it behind a clean form.

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Update it by chatting

Prices move. Ask Claude to change a rate, add an option, or insert a step and the live form updates in seconds. No developer, no redeploy.

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Backtest before you publish

Run your last 20 real jobs through it and tune the formula until the live estimate matches what you actually charge. Ship it once it lines up.

How this form was built

No template builder and no code. One message to Claude with the CalcForms connector switched on:

✦ Claude with the CalcForms connector

Build an auto loan calculator from my F&I workbook. Look up APR by credit tier from the Rate Sheet tab, subtract trade-in and down payment, add sales tax and a 699 dollar doc fee, then run PMT for the monthly payment. Let the buyer pick term from 36 to 84 months.

Done. I built Auto Loan Calculator with your pricing and deployed it to forms.badabingapp.cc. The math runs server-side and every submission is saved with the inputs and email. Want to add a field or change a rate? Just tell me.

Build this exact form

CalcForms is a connector you add to Claude once. After that you build and edit forms just by chatting.

Add CalcForms to Claude. Open the Add custom connector dialog, name it Calcforms, and paste https://forms.badabingapp.cc. One time, about 60 seconds.
Paste the prompt below. Claude builds the form, wires in your math, and hands you a live URL.
Share it, then tweak by chatting. Put it on your site or send the link. Change a rate or add a field later just by asking.

Copy this prompt into Claude

"Build an auto loan calculator from my F&I workbook. Look up APR by credit tier from the Rate Sheet tab, subtract trade-in and down payment, add sales tax and a 699 dollar doc fee, then run PMT for the monthly payment. Let the buyer pick term from 36 to 84 months."

Example run: A shopper picks a 38,000 dollar vehicle with 9,000 trade-in and 3,000 down on 72 months in the Good tier. The form shows about 465 dollars per month, then sends you the lead with vehicle, trade equity and credit tier attached.

New to connectors? A connector (an MCP server) is a secure link between Claude and an app. The CalcForms connector lets Claude build, deploy, and update real calculator forms for you, all from the chat window.

Formulas it supports

Amount financed: (price - trade_in - down_payment) + sales_tax + doc_fee
APR: VLOOKUP(credit_tier, rate_sheet, 2)
Sales tax: (price - trade_in) * tax_rate
Monthly payment: PMT(APR/12, term_months, -amount_financed)
Total of payments: monthly_payment * term_months

FAQ

Can it price different APRs by credit tier?

Yes. It pulls APR straight from your rate sheet by tier, so a 720-plus buyer and a subprime buyer each see the payment your lenders would actually quote them.

Does it handle trade-in and tax on the difference?

Yes. It subtracts trade-in and down payment, then applies sales tax on the taxable amount per your state rules, plus any doc or dealer fees you set.

What if my lender incentives change next month?

Ask Claude to update the rate tiers or incentives and the live calculator reflects it immediately, no rebuild required.

Build yours in the next 10 minutes.

Your first form is free. No credit card.

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