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About

Embed Digital Calculator on Your Site

Add accurate, tax-aware financial calculators to your website in minutes. Iframe widgets for quick embedding, a REST API for custom integrations, and a Model Context Protocol (MCP) server for AI agents. Free to start, MIT-licensed, no signup required.

Jump to the quickstart →

What you can embed

Digital Calculator gives you three integration surfaces depending on how deeply you want to embed financial math into your product. All three share the same vetted calculation engines — IRS 2026 tax brackets, SSA bend points, current contribution limits — so results are consistent across every channel.

  • Embed a single calculator — Drop a full calculator (mortgage, 401(k), paycheck, etc.) onto any page with one iframe tag. Best for marketing pages, blog posts, and resource hubs.
  • Embed a widget — Use one of our compact, focused widgets (mortgage payment, IRA contribution, savings goal, and more) when you need a lightweight tool inside a larger flow.
  • REST API — Call our calculation engines directly over HTTPS. JSON in, JSON out. Ideal for advisor dashboards, mobile apps, and back-office systems.
  • MCP server for AI agents — Already live. Connect Claude Desktop, MCP Inspector, or any MCP-compatible agent to 5 deterministic financial calculator tools. Production-ready today.

Getting started

Most teams can ship an embedded calculator in three steps. Here is the fastest path — embedding the mortgage calculator on a marketing page:

Step 1: Copy the embed snippet

Add an iframe pointing at the calculator you want to embed. No script tags, no build step, no dependencies:

html 
<iframe
  src="https://www.digitalcalculator.info/mortgage-calculator/?embed=1"
  width="100%"
  height="780"
  loading="lazy"
  title="Mortgage Calculator"
  style="border:0;border-radius:8px;">
</iframe>

Step 2: Style the frame

The calculator inherits its own design tokens, so you do not need to write any calculator CSS. Wrap the iframe in your container, give it a max-width that matches your content column, and you are done.

Step 3: Track conversions (optional)

Want to know when visitors actually use the embedded calculator? Pass a callback query parameter and listen for postMessage events on your parent page. See Embed a single calculator for the event schema.

Use cases

Different teams use the embeds in different ways. Here is how four common audiences typically deploy them:

Financial advisors and wealth managers

Embed retirement, 401(k), and Social Security calculators directly on your client portal or planning pages. Clients run scenarios on their own time, which gives you better-prepared meetings and a documentation trail of the projections discussed.

Banks, credit unions, and lenders

Drop mortgage, auto loan, and APR calculators on rate pages, loan-product pages, and pre-qualification flows. The calculators stay current with federal rate caps and APR disclosure rules without your team having to maintain the math.

Fintech startups and product teams

Use the REST API to build native experiences on top of vetted calculation engines. Ship faster on your core differentiation by not rebuilding amortization schedules, tax bracket math, or compound-interest formulas from scratch.

Educational sites and creators

Personal-finance bloggers, YouTube creators, and education sites embed calculators alongside their content so readers can apply concepts immediately. Free tier covers most non-commercial use with attribution.

Pricing

Embedding is free for non-commercial use and most low-volume commercial use. Commercial licensing — including white-label removal of the "Powered by Digital Calculator" attribution, custom theming, SLA guarantees, and dedicated support — is available on request. Open a GitHub issue or email us through the For Business page to discuss your needs. We have not yet enabled self-serve paid plans because we want each commercial partnership to start with a real conversation.

Why this instead of building it yourself

  • Always current — IRS 2026 limits, SSA bend points, and tax brackets are updated as soon as they are announced. You inherit those updates automatically.
  • Math you can audit — Calculators are open source and tested via Vitest parity suites. Reference the GitHub repo if your compliance team needs to verify a formula.
  • No vendor lock-in — Same engines power the public site, the MCP server, and the REST API. If you decide to bring math in-house later, the formulas are documented and the API contract is stable.
  • YMYL-safe out of the box — Every response includes a disclaimer link and a methodology reference. Your legal team gets a defensible audit trail by default.

Frequently asked questions

Do I need to register or get an API key to embed a calculator?

No. Iframe embeds and the MCP server are open and require no signup. The REST API currently has a 100 requests per minute throttle per IP, with no per-user metering. If you need higher limits or a dedicated quota, reach out for a commercial agreement.

Can I remove the "Powered by Digital Calculator" attribution?

The free tier requires keeping the attribution visible on embedded calculators. White-label removal is part of the commercial license. Contact us through the For Business page to discuss pricing.

Can I customize the colors and branding?

Iframe embeds inherit Digital Calculator's Slate & Copper theme by default. Custom theming via CSS variables is available on the commercial tier. For full control, use the REST API to build a native UI using your own design system — the calculation engines stay the same.

What happens if Digital Calculator changes a calculator after I embed it?

Calculation changes are backward-compatible unless legally required otherwise (for example, a new IRS contribution limit). UX changes can happen on the public iframe. If you need a frozen, versioned experience, use the REST API — we ship versioned response envelopes including an engineVersion field so your team can pin behavior.

Is this MIT-licensed? Can I use it in a commercial product?

The MCP server (@markcolabs/mcp on npm) is MIT-licensed. The iframe embeds and REST API are governed by the Digital Calculator Terms of Use — non-commercial embedding is free; commercial embedding above modest volume requires a commercial license. Get in touch and we will sort out the right tier for your use case.

Next steps