Description
Add a free, working calculator to any post or page with one shortcode. Pick a calculator, paste [calculate_at calculator="mortgage-calculator"], publish. There is nothing to configure: no account, no API key, no settings page.
The calculators run on calculate.at, so they always use the latest formulas and you never have to update anything. Each one resizes itself to fit its content (no scrollbar, no dead space) and works on phones, tablets and desktops.
Calculators you can embed
- Mortgage calculator (
mortgage-calculator): monthly principal and interest, total payment with property tax and home insurance, total interest and loan amount from home price, down payment, rate and term. Good for real estate, mortgage and finance sites. - BMI calculator (
bmi-calculator): body mass index in metric (cm, kg) or imperial (ft, in, lb) with the standard adult categories. Good for health, fitness and wellness blogs. - Tip calculator (
tip-calculator): tip amount, total bill and split-the-bill share per person with 15%, 18%, 20% and 25% presets or a custom percentage. Good for restaurant, travel and lifestyle sites. - Percentage calculator (
percentage-calculator): what is X% of Y, X is what percent of Y, and X is Y% of what number. Good for education, business and how-to sites. - Miles to km converter (
miles-to-km): convert miles to kilometers with the exact factor 1 mile = 1.609344 km, with common race distances. Good for running, travel and cycling blogs.
How to use
- Install and activate the plugin.
- Edit a post or page and add the shortcode, for example
[calculate_at calculator="tip-calculator"]. In the block editor use the Shortcode block; it also works in the Classic Editor and in page builders that have a shortcode element. - Publish. That is all.
Use the shortcode more than once with different calculator values to put several calculators on the same page.
Why use it
- Free, no signup. No account, API key or registration, ever required.
- Always up to date. The embedded calculator is a live page on calculate.at, so fixes and improvements arrive without a plugin update.
- Responsive and fast. The iframe is lazy-loaded, sized automatically, and only one tiny inline script is added per page (for the auto-resize).
- No cookies, no tracking from the calculator. The embedded calculator page loads no analytics scripts and sets no cookies.
- Clear results. Each calculator shows its result instantly and links to the full calculator page on calculate.at for more detail.
Want another calculator, a translation or a white-label version? Contact calculate.at: custom calculators, translations and builds without the attribution footer are available on request.
External service
This plugin displays calculators hosted on calculate.at, so it works only while calculate.at is reachable. When a page containing the shortcode is opened, the visitor’s browser loads the calculator from https://calculate.at/embed/<calculator>/ inside an iframe. That request sends the visitor’s IP address and browser details to calculate.at, like any web request. The plugin itself sends no other data, and the calculator page sets no cookies and runs no analytics. Values a visitor types into a calculator stay in their browser. Service terms: https://calculate.at/terms/. Privacy policy: https://calculate.at/privacy-policy/.
Disclaimer
The calculators give estimates for information only. They are not financial, medical or tax advice; a BMI value is a screening measure for adults, not a diagnosis.
Screenshots





Installation
- Install and activate the plugin through the WordPress admin (Plugins > Add New), or upload the plugin folder to
/wp-content/plugins/. - Add a shortcode to any post or page, for example
[calculate_at calculator="mortgage-calculator"]. - Publish. No configuration is needed.
FAQ
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How do I add a mortgage calculator to my WordPress site?
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Install this plugin, edit the page where you want it, add a Shortcode block and type
[calculate_at calculator="mortgage-calculator"]. Publish and the calculator appears in place. -
Which calculators are available?
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mortgage-calculator,
bmi-calculator,tip-calculator,percentage-calculatorandmiles-to-km. Example:[calculate_at calculator="bmi-calculator"]. More may be added over time; the current list is at calculate.at/embed-calculators. -
Do I need an account or an API key?
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No. The plugin and the calculators are free and need no account, API key or configuration.
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Does it work with the block editor, Classic Editor and page builders?
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It works anywhere WordPress shortcodes work: the Shortcode block in the block editor, the Classic Editor, and shortcode elements in most page builders.
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Is the calculator responsive?
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Yes. It fills the width of its container up to 480 px, resizes its own height to its content, and works on mobile screens.
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Does it slow down my site?
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Very little. The calculator loads in a lazy-loaded iframe, so it does not block your page. One small inline script is added once per page, however many calculators you embed, to handle auto-resizing.
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The embedded calculator page sets no cookies and loads no analytics. Like any embedded page, it is requested from calculate.at, which receives the visitor’s IP address in a normal server request. See the External service section above.
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Can I embed more than one calculator on the same page?
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Yes. Use the shortcode several times with different
calculatorvalues. -
Which currency and units do the calculators use?
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The mortgage and tip calculators work in US dollars. The BMI calculator supports metric and imperial units, and the miles-to-km converter converts miles to kilometers.
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Is this free? Can I remove the calculate.at link?
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The plugin and every calculator it embeds are free, provided the small attribution footer (the calculate.at and calculator-name links under the embed) stays in place. That footer is how the service stays free. If you need a version without it, contact calculate.at about a white-label build.
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I need a calculator that is not listed.
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Contact calculate.at with what you need. Requests for new calculators, translations and customizations are welcome.
Reviews
There are no reviews for this plugin.
Contributors & Developers
“calculate.at Calculators – Mortgage, BMI, Tip, Percentage & Unit Converter” is open source software. The following people have contributed to this plugin.
ContributorsInterested in development?
Browse the code, check out the SVN repository, or subscribe to the development log by RSS.
Changelog
1.0.1
- Improved WordPress.org listing: clearer plugin name and description, icon, banner and screenshots, external service and privacy details, expanded FAQ. No change to how the shortcode works.
1.0.0
- Initial release: tip, mortgage, BMI, percentage and miles-to-km calculators.
