Free embeddable mortgage calculators
Built for mortgage brokers, realtors, lenders, banks, credit unions, and financial bloggers. Drop a calculator on your site in a minute.
Dett.io is owned by Knowe LLC. Same math as the main site. No lead forms.
Made for the people who talk to borrowers every day
Keep clients on your site. Look like the expert who shows the numbers. Embed them, free, forever.
For Realtors
Help buyers see the budget before the first showing.
Put Affordability, True Monthly Cost, and Rent vs Buy on listing pages and your site. Serious buyers arrive already oriented — and you look like the agent who tells the truth.
Suggested calculatorsFor Brokers & Loan Officers
Clients run the numbers before they call you.
Refinance, DTI, and Best Loan for My Timeline turn your website into a resource hub. People show up pre-educated, and you never pay for another lead-gen widget.
Suggested calculatorsFor Lenders, Banks & CUs
The full suite, on your site, with zero engineering.
Offer every Dett calculator — FHA, VA, conventional, closing costs — without building or maintaining tools. Borrowers self-select the right product and submit cleaner applications.
Suggested calculatorsFor Financial Bloggers
Turn a static post into an interactive tool.
Drop the relevant calculator next to the article. Readers stay longer, share more, and you never pay an affiliate for a widget that spies on them.
Suggested calculatorsChoose a calculator
True Monthly Mortgage Cost
CoreHow Much House Can I Afford?
CoreDown Payment Strategy
CoreRent vs Buy Analysis
CoreRefinance Break-Even
CoreCash-Out Refinance
CoreRecast vs Refinance
CoreBest Loan for My Timeline
ComparisonPay Off Faster
PayoffRate Sensitivity
PayoffAmortization Schedule
PayoffDTI Calculator
QualificationClosing Cost Estimator
QualificationPMI Calculator
QualificationFHA Loan Calculator
QualificationVA Loan Calculator
QualificationCustomize
Look and feel
Default inputs for Refinance
Live preview
Copy the snippet
Paste this on any page. The iframe loads the calculator and a tiny script listens for postMessage to grow with the content.
Install guides
In the block editor, add a Custom HTML block and paste the snippet. On classic themes, a Custom HTML widget in a sidebar also works. If a security plugin strips iframes, allow dett.io. Do not run the snippet through a visual editor that rewrites HTML.
Edit the page, add a Code Block, and paste the snippet. Squarespace Business plans and above support Code Blocks. Set the block to span the full content width so the calculator can breathe on mobile.
Add an Embed HTML / Embed a widget element, paste the snippet, and stretch the element to the width you want. If you use the auto-resize script, give the embed element room to grow vertically.
Drag an Embed element onto the canvas, paste the snippet, and publish. Put it in a container with a max width of ~900px for a comfortable reading column, or full-bleed for a resource page.
FAQ
Is this really free?
Yes — embed them, free, forever. No signup, no API key, no usage limits, no watermark beyond the small “Powered by Dett.io” link. Dett.io is owned by Knowe LLC. We are not a lender and we do not take leads.
Do I have to credit Dett.io?
Yes. The free embed includes a small do-follow “Powered by Dett.io” link back to the matching calculator page. That credit is the entire price. Please leave it in place.
Do you track my visitors or their numbers?
No. Calculator inputs stay in the visitor’s browser. We do not collect names, emails, or the numbers they type. We only record that an embed loaded, counted by referring domain, so we can see which sites use the widgets.
Will it slow down my site?
The optional loader script is a few kilobytes and loads asynchronously. The calculator itself runs inside an iframe, so it cannot block your page. Auto-height uses postMessage — no polling of your DOM.
Does it work on mobile?
Yes. Widgets are responsive, and the auto-resize loader grows the iframe to fit on phones and desktops.
Who do I contact for support?
Email hello@dett.io. For privacy questions, privacy@dett.io. We usually reply within a few business days.
Questions? hello@dett.io · Privacy · All calculators