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Personal Finance · Money Concepts

Rule of 72 Calculator

How many years it takes your money to double at a given rate — and what it grows to.

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

Try the Rule of 72 Calculator

Enter a rate — your doubling time updates as you type.

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Estimates only — not a loan offer or financial advice.

Put this calculator on your website

What this calculator does

What the Rule of 72 calculator works out

The Rule of 72 Calculator is a free, embeddable calculator from CalcFunnel. How many years it takes your money to double at a given rate — and what it grows to.

You enter 3 inputs: annual return rate (%), starting amount and time horizon (years).

It returns years to double, number of doublings, future value, growth multiple and exact doubling time.

Built for financial coaches and educators. Embedding it on your own website needs the Pro plan (from $150/month, with a 14-day free trial), which unlocks the Personal Finance category.

Results it shows

  1. 01Years to Double
  2. 02Number of Doublings
  3. 03Future Value
  4. 04Growth Multiple
  5. 05Exact Doubling Time

The first figure — years to double — 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.

Annual Return Rate (%)
The annual growth rate of your money, compounded yearly.
Starting Amount
An optional starting balance, to project future value.
Time Horizon (years)
How many years to project.

For your website

Embed this calculator on your website

Put the Rule of 72 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

Rule of 72 calculator FAQs

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

Q.01What does the Rule of 72 Calculator calculate?
How many years it takes your money to double at a given rate — and what it grows to. It returns years to double, number of doublings, future value, growth multiple and exact doubling time.
Q.02What information do I need to use the Rule of 72 Calculator?
You enter 3 inputs: annual return rate (%), starting amount and time horizon (years). Every input starts with a sensible default, so you can change only what you know.
Q.03What does “Annual Return Rate (%)” mean in the Rule of 72 Calculator?
The annual growth rate of your money, compounded yearly.
Q.04What does “Starting Amount” mean in the Rule of 72 Calculator?
An optional starting balance, to project future value.
Q.05Is the Rule of 72 Calculator free to use?
Yes — you can use it on this page for free, without an account. Embedding it on your own website needs the Pro plan (from $150/month, with a 14-day free trial), which unlocks the Personal Finance category. Compare plans.
Q.06Can I embed the Rule of 72 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 Rule of 72 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 Rule of 72 results financial advice?
No. The Rule of 72 is an approximation (most accurate near 8%); the exact doubling time assumes annual compounding. Investment returns are not guaranteed.

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The Rule of 72 Calculator is one of 188 calculators you can brand and embed with one line of code.

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