🏠 Florida Mortgage Calculator
A standalone, embeddable mortgage calculator widget for Florida home buyers — vanilla HTML/CSS/JS, zero dependencies, no build step.
![Screenshot placeholder: add a screenshot of the calculator here as screenshot.png]
What it calculates
Monthly PITI (principal + interest + taxes + insurance), plus:
- Monthly breakdown — P&I, property taxes, homeowners insurance, PMI
- Loan summary — loan amount, down-payment %, total interest, payoff date
- Year-by-year amortization schedule — interest, principal, and remaining balance per year
- PMI logic — if the down payment is under 20%, an illustrative PMI estimate (0.5% of the loan per year) is added and labeled as an estimate; at 20%+ down, no PMI is shown
Florida defaults
| Input | Default | Why |
|---|---|---|
| Home price | $415,000 | Florida single-family median (Sept 2026 data) |
| Down payment | $83,000 (20%) | Standard conventional threshold — avoids PMI |
| Interest rate | 6.95% | Rate context used on Estate Path |
| Term | 30 years | Most common US mortgage term |
| Property tax | 0.85% / yr | Florida default used on Estate Path |
| Homeowners insurance | $8,471 / yr | Florida average used on Estate Path |
Verified math
The defaults were checked in code (Node) against the Estate Path calculator:
| Scenario | This widget | Estate Path |
|---|---|---|
| $415K, 20% down, 6.95%, 30 yr | $3,198/mo ($3,197.54) | $3,198/mo |
| $500K, 20% down, 6.95%, 30 yr | $3,708/mo ($3,707.87) | $3,708/mo |
Breakdown at the defaults: P&I $2,197.67 + taxes $293.96 + insurance $705.92 = $3,197.54 → $3,198. Total interest over 30 years: $459,160.
Quick start (demo)
# Just open it — no server needed
open index.html
Embed on your own site
Option A — direct embed (recommended). Copy calculator.js and calculator.css to your site, then paste this where you want the widget:
<link rel="stylesheet" href="calculator.css">
<div data-fmc-widget>
<!-- copy the widget markup from index.html here -->
</div>
<script src="calculator.js"></script>
The widget auto-initializes on any element with data-fmc-widget. All styles are scoped under that attribute, so it won't clash with your page's CSS. Inputs use data-fmc="price|down|rate|term|tax|insurance" and outputs use data-fmc-out="total|pi|tax|insurance|pmi|loan|downpct|interest|payoff".
Option B — iframe. Host index.html somewhere and embed it:
<iframe src="https://your-site.com/florida-mortgage-calculator/"
width="100%" height="900" style="border:0"></iframe>
Option C — use just the math. computeMortgage() is exported for Node and as window.FloridaMortgageCalculator:
const { computeMortgage } = require('./calculator.js');
const r = computeMortgage({
price: 415000, downPayment: 83000, rate: 6.95,
termYears: 30, taxRate: 0.0085, insuranceAnnual: 8471
});
console.log(r.monthlyTotal); // 3197.54
Disclaimer
Estimate only — not a lending offer, pre-approval, or quote. Taxes vary by Florida county, insurance varies by carrier and property, and PMI varies by lender and credit profile. HOA dues are not included.
License
MIT — see LICENSE.
Author
Syed Shahid / Syed Ventures
