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Mortgage & Home Loans · Alternative & Specialty

Interest Only Mortgage Calculator

See your low interest-only payment and the higher payment once the loan starts amortizing.

  • Free to use here · embed on the Free plan
  • 4 inputs · 5 results
  • English & Spanish

Try the Interest Only Mortgage Calculator

See your interest-only payment and the jump after the IO period — results update as you type.

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Estimates only — not a loan offer or financial advice.

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What this calculator does

What the Interest Only Mortgage calculator works out

The Interest Only Mortgage Calculator is a free, embeddable calculator from CalcFunnel. See your low interest-only payment and the higher payment once the loan starts amortizing.

You enter 4 inputs: loan amount, interest rate (%), loan term (years) and interest-only period (years).

It returns interest-only payment, payment after IO period, payment increase, total interest and total cost.

Built for loan officers, brokers and homebuyers. Embedding it on your own website is included on the Free plan (free forever for up to 5 calculators on one domain), as part of the Mortgage & Home Loans category.

Results it shows

  1. 01Interest-Only Payment
  2. 02Payment After IO Period
  3. 03Payment Increase
  4. 04Total Interest
  5. 05Total Cost

The first figure — interest-only payment — is the headline result.

Inputs

The inputs it uses

Each field below comes straight from the calculator, with the same help text visitors see when they hover the info icon.

Loan Amount
The original balance of your mortgage loan.
Interest Rate (%)
The annual interest rate on your mortgage. The same rate applies during both the interest-only and amortizing periods.
Loan Term (years)
The full repayment term of the loan in years, including both the interest-only and amortizing periods.
Interest-Only Period (years)
How many years you pay interest only before the loan begins amortizing. After this period the full balance is repaid over the remaining term, raising your payment.

For your website

Embed this calculator on your website

Put the Interest Only Mortgage Calculator on your own site with your colors, copy and lead form. Every calculation can arrive in your CRM with the numbers attached.

Works on WordPress, Wix, Squarespace, Webflow, Shopify, GoHighLevel and plain HTML — paste one line into an HTML or code block. No plugin needed.

Start free How embedding works

Free plan, no card. 14-day trial on Pro & Business.

  1. Inline on any pagePaste the snippet where the calculator should appear. It fills the width of its container and resizes to fit its content.
  2. Popup buttonA button sits on your page; visitors click it and the calculator opens in a popup.
  3. Floating corner widgetPaste once — or in your site-wide footer code — to show a floating calculator bubble in the corner of every page.
  4. Open from your own link or buttonGive any existing link, button or image a class and it opens the calculator when clicked.
  5. Direct linkA full-page link to the calculator for emails, social posts, QR codes or a menu item.

FAQ

Interest Only Mortgage calculator FAQs

Still stuck? Ask the team — we reply within one business day.

Q.01What does the Interest Only Mortgage Calculator calculate?
See your low interest-only payment and the higher payment once the loan starts amortizing. It returns interest-only payment, payment after IO period, payment increase, total interest and total cost.
Q.02What information do I need to use the Interest Only Mortgage Calculator?
You enter 4 inputs: loan amount, interest rate (%), loan term (years) and interest-only period (years). Every input starts with a sensible default, so you can change only what you know.
Q.03What does “Loan Amount” mean in the Interest Only Mortgage Calculator?
The original balance of your mortgage loan.
Q.04What does “Interest Rate (%)” mean in the Interest Only Mortgage Calculator?
The annual interest rate on your mortgage. The same rate applies during both the interest-only and amortizing periods.
Q.05Is the Interest Only Mortgage Calculator free to use?
Yes — you can use it on this page for free, without an account. Embedding it on your own website is included on the Free plan (free forever for up to 5 calculators on one domain), as part of the Mortgage & Home Loans category. Compare plans.
Q.06Can I embed the Interest Only Mortgage Calculator on my website?
Yes. Embed it inline, as a popup button, as a floating corner widget, from your own link or button, or share a direct link. It works on WordPress, Wix, Squarespace, Webflow, Shopify, GoHighLevel and plain HTML sites with one line of code — see embedding.
Q.07Is the Interest Only Mortgage Calculator available in Spanish?
Yes. Labels, tooltips and result names are available in English and Spanish, and visitors can switch language in the calculator.
Q.08Can the calculator capture leads?
Yes. It can end with a lead form, a Get a Quote form, a Share panel or a button to any URL. Leads are saved with the inputs and results attached and can be forwarded to your CRM by webhook.
Q.09Are the Interest Only Mortgage results financial advice?
No. Estimates only. During the interest-only period no principal is repaid, so the full balance remains due when the amortizing period begins. Confirm terms with your lender.

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