Put this calculator on your site

The comparison app on this site can now sit inside another website. A test version is live. Paste this where you want it:

<iframe id="stackup" src="https://multifamily.online/embed/calculator/" width="100%" height="1200" style="border:0" title="Multifamily loan comparison by Stackup" loading="lazy"></iframe>
<script>addEventListener('message',function(e){if(e.origin==='https://multifamily.online'&&e.data&&e.data.stackupHeight)document.getElementById('stackup').height=e.data.stackupHeight})</script>

Give it the full width of your content column. The app is tall: the ranked table runs about 3,700 pixels on a desktop and longer on a phone, where the rows turn into cards. The second line is optional. With it, the frame grows to fit the app as the borrower types; the app sends only its height, and the line accepts messages from multifamily.online and nothing else. Without it, the frame stays 1,200 pixels tall and scrolls inside.

What’s in the test version

The same app as our home page: the four steps, the live pane with the largest estimate, and every program ranked by the loan it allows, with the constraint that caps each one. It runs on the same program book, so when we update a limit here, your copy shows it too. The Treasury yields update from the same daily feed.

What it leaves out: our header, footer and analytics, and the request form to our desk. Links to program terms and the method open multifamily.online in a new tab, and there’s a small “Powered by Stackup” credit at the bottom. The disclosures stay in (estimate, not an offer; no agency affiliation).

What isn’t built yet

Your name and colors, choosing which programs show, and sending the borrower’s request to you instead of to the Janover Capital desk. A HUD lender might want only the FHA rows; a listing site might want it prefilled from a property page. Tell us which of those you’d need.

The rate ticker

If you only want the rates, this one is smaller:

<iframe src="https://multifamily.online/embed/rates?ids=UST5,UST7,UST10,SOFR" width="100%" height="150" style="border:0" title="Rates from Stackup" loading="lazy"></iframe>

It shows the 5, 7 and 10-year Treasury and SOFR with their dates and week-over-week change, and credits the publishers. The JSON behind it is described on the method page.

What it won’t do

It won’t quote rates or issue approvals, on your site or ours.

Interested

Email hello@multifamily.online with “embed” in the subject, your site, and the programs you’d want shown. There’s no price list yet and no one else is using it yet.