How to Calculate Percentages (4 Methods)
Master four essential percentage formulas: find X% of Y, figure out what percent X is of Y, calculate percentage increase/decrease, and percentage difference.
How to Calculate Standard Deviation (Step by Step)
Learn to calculate standard deviation and variance for populations and samples. Covers formulas, z-scores, normal distribution, and real-world interpretation with worked examples.
How to Calculate Tips Quickly (Mental Math)
Learn mental math shortcuts for calculating 15%, 18%, and 20% tips instantly. Covers tipping etiquette by service type, splitting bills, and international customs.
How to Calculate Volume (3D Shapes & Practical Uses)
Master volume formulas for cubes, cylinders, spheres, cones, and irregular objects. Includes unit conversions, the displacement method, and real-world examples.
How to Check Domain WHOIS Information
Learn how to look up domain WHOIS records, understand registration and expiry dates, check domain ownership, and read RDAP data for any website.
How to Check and Fix HTTP Security Headers
Learn how to audit HTTP security headers, understand Content-Security-Policy, HSTS, X-Frame-Options, and protect your website from common web attacks.
How to Check SSL Certificate Status and Expiry
Learn how to verify SSL certificates, understand TLS 1.2 vs 1.3 differences, check certificate chains and expiry dates, and monitor HTTPS security for your sites.
How to Convert Temperature (Fahrenheit, Celsius & Kelvin)
Master temperature conversion formulas between Fahrenheit, Celsius, and Kelvin with reference points, worked examples, and a cooking temperature chart.
How to Convert Roman Numerals (Rules & Examples)
Learn how to read and write Roman numerals with the seven base symbols, subtractive notation rules, worked examples for dates, and tips for avoiding mistakes.
How to Convert CSV to JSON (And Back Again)
Learn CSV and JSON structure, when to use each format, and how to handle delimiters, quoted fields, header rows, and type inference when converting between them.
How to Convert Time Zones (Quick Guide)
Master time zone conversions with this practical guide. Covers UTC offsets, daylight saving, the International Date Line, and scheduling across global teams.
How to Convert Units of Measurement (Complete Guide)
Learn how to convert between metric and imperial units for length, weight, volume, and temperature with formulas, conversion factors, and mental math shortcuts.
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