Try it yourself
This is a real, working CalcForms calculator, right here on the page. Enter your details and watch the estimate update on the spot. It is exactly what your customers would use, and every submission reaches you as a lead.
What your customer answers
The live form above asks for these, in this order.
- Their email, so the lead reaches you
- Vehicle price: a number
- Trade-in value: a number
- Down payment: a number
- Loan term: 36 months, 48 months, 60 months, 72 months, 84 months
- Credit tier: Excellent 720+, Good 660-719, Fair 600-659, Subprime below 600
What they see: Estimated monthly payment, worked out from their answers on the spot.
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 ChatGPT
- Backtest against booked deals so quoted payments line up with what your lenders actually approve
Why it closes more deals
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.
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.
Update it by chatting
Prices move. Ask ChatGPT to change a rate, add an option, or insert a step and the live form updates in seconds. No developer, no redeploy.
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.
Why calculator forms are worth it, by the numbers
47.3% vs 2.8%
In an analysis of 50,000+ forms, interactive forms averaged a 47.3% conversion rate versus 2.8% for static forms. (Outgrow)
51% of buyers
51% of B2B software buyers now begin their research in an AI chatbot rather than a search engine. (G2, 2026)
1 in 3
A third of B2B buyers have chosen a vendor they had never heard of before, on an AI assistant's recommendation. (G2, 2026)
How this form was built
No template builder and no code. One message to ChatGPT with CalcForms added:
Build this exact form
CalcForms is an app you add to ChatGPT once. After that you build and edit forms just by chatting. Works in Claude too.
- Add CalcForms to ChatGPT. Open the CalcForms app page, click Install plugin, and sign in with your email. One time, about 60 seconds. A free ChatGPT account works. (Using Claude? Setup here.)
- Say the words below. ChatGPT builds the form with your math inside and gives you a link.
- Share it, then change it by asking. Send the link to customers. Change a rate or add a question later just by asking.
Step-by-step: turn your spreadsheet into a form, add your price list, show customers one number. All guides →
"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."
How does it work? CalcForms is an official ChatGPT app. Once it is added, ChatGPT can build, publish and update real calculator forms for you, all from the chat window. Your customers never need ChatGPT; they just open a link.
What it works out
Monthly paymentTrade-in and down paymentRate by creditTotal cost
Last updated 6 October 2026
FAQ
Can it price different APRs by credit tier?
Does it handle trade-in and tax on the difference?
What if my lender incentives change next month?
Build yours in the next 10 minutes.
Free in ChatGPT, unlimited forms and submissions. No credit card.
Add to ChatGPT, free →