code For bloggers, webmasters & content creators

Free embeddable calculators for your blog

Drop 24+ working calculators into your site with one copy-paste iframe. No signup, no API keys, no rate limits — just better content for your readers. Each embed credits Calculators.im with a small attribution link.

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No paywall, no quotas

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Zero impact on LCP

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Jump to your audience

24 calculators · 5 verticals
savings Personal Finance & Money Bloggers (3) favorite Health, Fitness & Wellness Bloggers (3) code Developer & Engineering Blogs (8) home_repair_service Home Improvement & DIY Sites (5) widgets General Utility & Lifestyle Sites (5)

How it works

1

Pick a calculator

Browse the sections below. Each calculator has a one-line description and a live preview link so you can see exactly what your readers will get.

2

Copy the snippet

Click "Show embed code" on any card and tap Copy. The snippet is a single iframe plus a small attribution paragraph. Works in WordPress, Ghost, Webflow, Substack, Squarespace, or plain HTML.

3

Paste & publish

Paste into any HTML block on your CMS and publish. The iframe loads lazily, scales to mobile, and updates automatically as we improve the calculator — no version maintenance on your side.

savings

Personal Finance & Money Bloggers

Mortgage, compound interest, and tipping tools for personal-finance writers, mortgage brokers, and money coaches.

Compound Interest Calculator

Use our free compound interest calculator to see how your investments grow over time with daily, monthly, quarterly, annual, or continuous compounding. Add monthly contributions, view a year-by-year growth table, and check your Rule of 72 doubling time.

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<iframe src="https://calculators.im/embed/compound-interest-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Compound Interest Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/compound-interest-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=compound-interest-calculator">Compound Interest Calculator</a> by Calculators.im</p>

Mortgage Calculator

Calculate your monthly mortgage payment with down payment using our free home loan calculator. Get instant results for mortgage cost, interest rates, and total loan amount. The most accurate house calculator for home buyers.

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<iframe src="https://calculators.im/embed/mortgage-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Mortgage Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/mortgage-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=mortgage-calculator">Mortgage Calculator</a> by Calculators.im</p>

Tip Calculator

Use our free tip calculator to calculate tip amount, total bill with tip, and split among friends. Perfect for restaurants, delivery, hotels, and any service with customizable tip percentages.

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<iframe src="https://calculators.im/embed/tip-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Tip Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/tip-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=tip-calculator">Tip Calculator</a> by Calculators.im</p>
favorite

Health, Fitness & Wellness Bloggers

BMI, TDEE, and pet-age tools for fitness coaches, nutrition bloggers, and pet-care sites.

BMI Calculator

Calculate your Body Mass Index (BMI), check where you fall on the BMI chart, find your ideal weight range, and understand what your BMI means for your health.

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<iframe src="https://calculators.im/embed/bmi-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="BMI Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/bmi-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=bmi-calculator">BMI Calculator</a> by Calculators.im</p>

Cat Age Calculator

Convert your cat's age into human years using the AAHA (American Animal Hospital Association) standard formula. Get life stage (kitten, junior, adult, mature, senior, geriatric), expected lifespan by breed and indoor/outdoor status, and age-appropriate health markers.

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<iframe src="https://calculators.im/embed/cat-age-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Cat Age Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/cat-age-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=cat-age-calculator">Cat Age Calculator</a> by Calculators.im</p>

TDEE Calculator

Calculate your Total Daily Energy Expenditure (TDEE) to know exactly how many calories you burn each day. Essential for weight loss, muscle gain, or maintaining your current weight.

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<iframe src="https://calculators.im/embed/tdee-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="TDEE Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/tdee-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=tdee-calculator">TDEE Calculator</a> by Calculators.im</p>
code

Developer & Engineering Blogs

JSON, YAML, diff, subnet, and converter tools for engineering blogs, tutorial sites, and dev newsletters.

Case Converter

Convert text to UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE and more — instantly with live preview. Designed for developers renaming variables and for writers formatting headings.

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<iframe src="https://calculators.im/embed/case-converter" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Case Converter by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/case-converter?utm_source=embed&utm_medium=snippet&utm_campaign=case-converter">Case Converter</a> by Calculators.im</p>

CSV to JSON Converter

Convert CSV to JSON online — fast, free, browser-side. Paste CSV, get clean JSON arrays with type-correct values, automatic header detection, RFC 4180 quoting, and one-click copy. Built for APIs, database imports, JavaScript datasets, and ETL pipelines.

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<iframe src="https://calculators.im/embed/csv-to-json-converter" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="CSV to JSON Converter by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/csv-to-json-converter?utm_source=embed&utm_medium=snippet&utm_campaign=csv-to-json-converter">CSV to JSON Converter</a> by Calculators.im</p>

Diff Checker

Compare two pieces of text, code, JSON, YAML or any plain-text file side by side. The diff checker highlights added, removed and changed lines with colour-coded marks and a similarity score. Runs entirely in your browser — your text never leaves the page.

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<iframe src="https://calculators.im/embed/diff-checker" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Diff Checker by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/diff-checker?utm_source=embed&utm_medium=snippet&utm_campaign=diff-checker">Diff Checker</a> by Calculators.im</p>

JSON Formatter

Format, validate, and minify JSON online. Pretty print with customizable indentation, syntax highlighting, error detection, and copy-to-clipboard. Essential developer tool for working with JSON data.

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<iframe src="https://calculators.im/embed/json-formatter" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="JSON Formatter by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/json-formatter?utm_source=embed&utm_medium=snippet&utm_campaign=json-formatter">JSON Formatter</a> by Calculators.im</p>

JSON to YAML Converter

Convert JSON to YAML online — fast, free, browser-side. Paste JSON, get clean YAML with correct indentation, type preservation, and quoting for ambiguous values. Built for APIs, Kubernetes manifests, Docker Compose, and Ansible playbooks.

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<iframe src="https://calculators.im/embed/json-to-yaml-converter" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="JSON to YAML Converter by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/json-to-yaml-converter?utm_source=embed&utm_medium=snippet&utm_campaign=json-to-yaml-converter">JSON to YAML Converter</a> by Calculators.im</p>

Markdown to HTML Converter

Convert Markdown to clean HTML instantly with GitHub Flavored Markdown support, live side-by-side preview, and one-click copy. Pure client-side rendering with no server roundtrip — your text never leaves your browser.

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<iframe src="https://calculators.im/embed/markdown-to-html-converter" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Markdown to HTML Converter by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/markdown-to-html-converter?utm_source=embed&utm_medium=snippet&utm_campaign=markdown-to-html-converter">Markdown to HTML Converter</a> by Calculators.im</p>

Subnet Calculator

Calculate subnet mask, network address, broadcast address, host range, and usable hosts from any IPv4 CIDR notation. Includes wildcard mask, binary representations, and a full CIDR cheat sheet.

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<iframe src="https://calculators.im/embed/subnet-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Subnet Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/subnet-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=subnet-calculator">Subnet Calculator</a> by Calculators.im</p>

YAML to JSON Converter

Convert YAML to JSON online — fast, free, browser-side. Paste any YAML and get clean JSON with type-correct numbers, booleans, null, arrays, and nested objects. Built for Kubernetes, Docker Compose, Ansible, OpenAPI, and CI/CD workflows.

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<iframe src="https://calculators.im/embed/yaml-to-json-converter" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="YAML to JSON Converter by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/yaml-to-json-converter?utm_source=embed&utm_medium=snippet&utm_campaign=yaml-to-json-converter">YAML to JSON Converter</a> by Calculators.im</p>
home_repair_service

Home Improvement & DIY Sites

Paint, tile, fence, carpet, and mulch estimators for home-improvement blogs and contractor sites.

Carpet Calculator

Calculate exactly how much carpet you need for any room or commercial space. Enter room dimensions and waste factor — get square footage, square yards, square meters, padding required, and total installed cost. Built for DIY homeowners and flooring contractors across US, UK, Canada and Australia.

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<iframe src="https://calculators.im/embed/carpet-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Carpet Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/carpet-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=carpet-calculator">Carpet Calculator</a> by Calculators.im</p>

Fence Calculator

Calculate posts, panels, gates, concrete and total cost for any residential or commercial fence project. Enter linear feet, post spacing, gate count and material type — get exact material list plus install cost. Built for DIY homeowners and fencing contractors across US, UK, Canada and Australia.

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<iframe src="https://calculators.im/embed/fence-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Fence Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/fence-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=fence-calculator">Fence Calculator</a> by Calculators.im</p>

Mulch Calculator

Calculate exactly how much mulch you need for any garden bed, tree ring, flower border or playground. Enter the bed dimensions, mulch depth and bag size — get cubic yards, cubic feet, bags needed, and total cost. Built for DIY gardeners and professional landscapers across US, UK, Canada and Australia.

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<iframe src="https://calculators.im/embed/mulch-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Mulch Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/mulch-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=mulch-calculator">Mulch Calculator</a> by Calculators.im</p>

Paint Calculator

Calculate exactly how much paint you need for any interior or exterior project. Enter room dimensions, doors, windows, and coats — get gallons or liters needed plus total cost. Built for DIY homeowners and professional contractors across US, UK, Canada, and Australia.

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<iframe src="https://calculators.im/embed/paint-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Paint Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/paint-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=paint-calculator">Paint Calculator</a> by Calculators.im</p>

Tile Calculator

Calculate exactly how many tiles you need for any floor, wall, bathroom or backsplash project. Enter room dimensions, tile size, grout joint width and waste factor — get tile count, boxes needed, and total project cost. Built for DIY homeowners and professional tile setters across US, UK, Canada and Australia.

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<iframe src="https://calculators.im/embed/tile-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Tile Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/tile-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=tile-calculator">Tile Calculator</a> by Calculators.im</p>
widgets

General Utility & Lifestyle Sites

Age, date, time, geometry, and grade tools for general-utility blogs and educator sites.

Age Calculator

Calculate your exact age in years, months, and days from your date of birth. Find out how old you are today, your age in days, weeks, hours, and countdown to your next birthday.

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<iframe src="https://calculators.im/embed/age-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Age Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/age-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=age-calculator">Age Calculator</a> by Calculators.im</p>

Circle Calculator

Free circle calculator — enter any one value (radius, diameter, circumference, or area) and instantly get the other three, plus sector, arc, and chord results.

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<iframe src="https://calculators.im/embed/circle-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Circle Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/circle-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=circle-calculator">Circle Calculator</a> by Calculators.im</p>

Date Calculator

Calculate days between two dates, add or subtract days from a date, find business days excluding weekends, and get accurate date differences in years, months, weeks, and days.

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<iframe src="https://calculators.im/embed/date-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Date Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/date-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=date-calculator">Date Calculator</a> by Calculators.im</p>

Grade Calculator

Calculate your final grade, current course grade, or what score you need on your final exam. Supports weighted assignments, multiple categories, and grade tracking.

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<iframe src="https://calculators.im/embed/grade-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Grade Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/grade-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=grade-calculator">Grade Calculator</a> by Calculators.im</p>

Time Calculator

Add, subtract, or find the difference between times in hours, minutes, and seconds. Supports HH:MM:SS format, AM/PM clock times, work hours with breaks, and instant conversion to total minutes or decimal hours.

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<iframe src="https://calculators.im/embed/time-calculator" width="100%" height="720" style="border:0;max-width:100%;" loading="lazy" title="Time Calculator by Calculators.im"></iframe>
<p style="font-size:12px;text-align:center;color:#64748b;margin-top:6px;">Powered by <a href="https://calculators.im/time-calculator?utm_source=embed&utm_medium=snippet&utm_campaign=time-calculator">Time Calculator</a> by Calculators.im</p>

Why embed instead of building your own?

Four reasons publishers use our embeds instead of coding calculators in-house.

timer

Zero maintenance

When tax tables change, RFC standards update, or formulas evolve, we ship the fix. Your embed picks it up automatically.

search

Better dwell time

Interactive tools keep readers on-page longer. Google rewards engagement signals. A 30-second calculator beats a static infographic.

trending_up

Conversion-ready

Mortgage brokers, financial advisors, and contractors use embeds to qualify leads. Reader runs the numbers, you become the obvious next step.

shield

No data collection

Calculations run client-side. We do not log inputs, do not require GDPR cookie banners on your side, and respect your privacy stance.

Frequently asked questions

Do I need permission or attribution credit? expand_more

No permission needed — embed any calculator on any site, commercial or personal. The snippet ships with a small "Powered by Calculators.im" attribution link beneath the iframe. Keeping the link is the only thing we ask in return.

Will this slow down my site? expand_more

The iframe ships with loading="lazy" so it does not load until a reader scrolls near it. Your above-the-fold content (LCP) is unaffected. Iframes are isolated from your page's JavaScript — no conflicts with existing scripts.

Does the embed work on mobile? expand_more

Yes. The iframe is set to width="100%" and the calculator inside is fully mobile-responsive. Default height is 720px; adjust per-calc if needed.

Can I customize the colors or branding? expand_more

Not yet in the v1 embed — calculators inside the iframe use neutral default styling that fits most blog designs. White-label/custom-theme embeds are on the roadmap. Drop us a line if you need a specific theme.

What if a calculator I want is not on the list? expand_more

We have 270+ calculators; the 24 listed here are the ones currently optimized for embed. Need a specific tool embedded? Ask — we usually prioritize embed-readiness for any calculator a blogger explicitly requests.

Need something custom?

Building a niche site that would benefit from a calculator we have not built yet? Running a high-traffic publication that wants priority on theme customization? Want to co-publish a calculator-driven guide?

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