Pro Calculators and Guides
How to Use Lorem Ipsum Placeholder Text in Designs and Websites
Generate placeholder text in paragraphs, sentences or words for mockups, layouts and templates, and learn when not to use it.
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Pro Calculators and Guides
Specialist calculators are only useful when you understand the rules behind the numbers. These guides explain what each professional calculator does, which inputs matter, how to read the result and where the official rules come from, covering payroll and tax, immigration and visas, housing, business compliance, engineering and science. Every guide links to a free tool that runs in your browser and keeps your figures private.
318 guides
Pro Calculators and Guides
How to Use the Pythagorean Theorem to Find a Missing Side (With Examples)
Find the hypotenuse or a leg of a right triangle using a² + b² = c², with area, perimeter and angles shown by the calculator.
Pro Calculators and Guides
How to Use Your Camera as a Mirror Online (Check Yourself Before a Call)
Turn on your webcam or phone camera to see yourself like in a mirror, flip the view, take a photo and download it. Nothing is recorded or uploaded.
Pro Calculators and Guides
How to Work Out Your UK Salary After Tax and National Insurance
See your take-home pay from a gross UK salary after income tax and National Insurance, per year, month and week, and understand each band.
Pro Calculators and Guides
How to Write a Resignation, Cover, Rent Receipt or Leave Letter and Save It as PDF
Use ready letter formats for resignation, cover letters, rent receipts, recommendations and leave requests, then save as a PDF.
Pro Calculators and Guides
How to Write an Application in Bangla (দরখাস্ত): Formats and Examples
A clear structure for Bangla application letters for leave, jobs, testimonials, TC and fee waiver, plus a free tool that formats them for you.
Pro Calculators and Guides
How to Write Markdown With a Live Preview and Export HTML or .md
Learn the most useful Markdown syntax and write with a live preview that you can copy as HTML or download as .md or .html.
Pro Calculators and Guides
Social Media Image Sizes: Instagram, Facebook, YouTube, X, LinkedIn, TikTok and More
A quick reference for the pixel sizes of posts, stories, covers and profile pictures on the main platforms, and how to avoid awkward cropping.
Pro Calculators and Guides
What Is a Healthy Weight for Your Height? Four Formulas Compared
Compare ideal weight from the Devine, Robinson, Miller and Hamwi formulas and the healthy BMI range, and learn why they differ.