Mortgage Calculator for Loan Officers

Try it yourself

This is a real, working CalcForms calculator embedded right 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 lands in your dashboard as a lead.

forms.badabingapp.cc/mortgage-calculator

What it calculates

Shows principal, interest, taxes, insurance and PMI as one live monthly payment while the borrower types
Keeps your exact payment formula, property-tax rates and PMI lookup tables from the spreadsheet you already price loans with
Captures every borrower as a pre-qualified lead with price, down payment, rate and DTI already calculated
Update rate sheets, county tax tables or LLPA adjustments later just by asking Claude, no rebuild
Backtest the form against past closings so the quoted payment matches what you actually funded

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.

Why calculator forms convert — by the numbers

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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)

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2× conversions

Interactive content generates roughly twice as many conversions as static content. (Content Marketing Institute)

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51% of buyers

51% of B2B software buyers now begin their research in an AI chatbot rather than a search engine. (G2, 2026)

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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 Claude with the CalcForms connector switched on:

✦ Claude with the CalcForms connector

Build a mortgage calculator from my pricing workbook. Use the PMT formula on the Amortization tab, pull property tax by state from the Tax Rates tab, and add PMI from the PMI lookup table when the down payment is under 20 percent. Output the full PITI payment.

Done. I built Mortgage 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 a mortgage calculator from my pricing workbook. Use the PMT formula on the Amortization tab, pull property tax by state from the Tax Rates tab, and add PMI from the PMI lookup table when the down payment is under 20 percent. Output the full PITI payment."

Example run: A borrower enters a 450,000 dollar home with 90,000 down at 6.75 percent over 30 years. The form returns roughly 2,940 dollars per month PITI, then sends you the lead with their price, 20 percent down and DTI already calculated.

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.

What it works out

Monthly payment
Property tax and insurance
PMI when needed
Total interest

FAQ

Does it include taxes, insurance and PMI, not just principal and interest?

Yes. It returns full PITI. Property tax comes from your state or county table, insurance from your factor, and PMI is added automatically from your lookup table whenever the down payment is below 20 percent.

Can I keep the exact amortization math from my spreadsheet?

Yes. CalcForms preserves your real Excel payment and pricing logic across tabs, so the borrower sees the same payment your own workbook produces.

How do I update rates when the market moves?

Just ask Claude. Tell it the new rate sheet or LLPA adjustments and the live form updates, no developer and no rebuild.

Build yours in the next 10 minutes.

Your first form is free. No credit card.

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