Articles & Guides
Deep dives into the tools we offer, their use cases, and tips for getting the most out of our platform.
Loan Calculator: How to Calculate Monthly Payments
Use our free loan calculator to find your monthly payment, total interest and full cost of any fixed-rate loan, with the formula and worked examples.
Percentage Calculator: How to Calculate Percentages
Find X% of a number, what percent one number is of another, and percentage change with our free percentage calculator, plus formulas and examples.
Compound Interest Calculator: Formula and Examples
Learn how compound interest works, with the formula, worked examples and a free compound interest calculator that projects savings with monthly deposits.
Inflation Calculator: What Your Money Is Worth Now
See what a past dollar amount is worth today with our free inflation calculator, based on US CPI data, and learn how to calculate inflation yourself.
Salary Converter: Hourly to Annual Pay and Back
Convert pay between hourly, daily, weekly, biweekly, monthly and yearly with our free salary converter, plus formulas to compare job offers fairly.
Tip Calculator: How Much to Tip and Split the Bill
Work out the tip and each person’s share in seconds with our free tip calculator, plus quick mental math and how tipping customs differ by country.
Discount Calculator: How to Calculate Sale Prices
Find the sale price and how much you save with our free discount calculator, plus the percent-off formula, stacked discounts and worked examples.
Sales Tax Calculator: Add or Remove Tax From a Price
Add sales tax to a price or back it out of a tax-inclusive total with our free sales tax calculator, with the formulas, examples and common mistakes.
ROI Calculator: How to Calculate Return on Investment
Calculate ROI and annualized return with our free ROI calculator. Learn the formulas, see worked examples and compare investments over different periods.
Length Converter Guide: Meters, Feet, Inches, Miles
Convert length between metric and imperial units with exact factors, worked examples and a free length converter for meters, feet, inches and miles.
Weight Conversion Guide: Kg to Lbs, Ounces, Stone
Convert kg to lbs, ounces, grams and stone with exact factors and worked examples, then check any weight instantly with our free weight converter.
Celsius to Fahrenheit: Temperature Scales Explained
Convert Celsius to Fahrenheit and Kelvin with exact formulas, a quick reference chart and worked examples, plus a free temperature converter.
Square Feet to Square Meters: Area Conversion Guide
Convert square feet to square meters, acres to hectares and more with exact factors, room and land examples, and our free online area converter.
Cups to Grams: How to Convert Cooking Measurements
Convert cups to grams for flour, sugar, butter and more. Get the formula, a baking conversion chart, and why weighing ingredients gives better results.
How Many MB in a GB? Data Storage Units Explained
Learn how many MB are in a GB, why a 1 TB drive shows 931 GB, and how bits and bytes differ, then convert sizes with our free data storage converter.
Speed Conversion Guide: km/h to mph, Knots, Mach
Convert km/h to mph, knots, m/s and Mach with exact factors and worked examples, then check any speed instantly with our free speed converter.
Liters to Gallons and More: Volume Conversion Guide
Convert liters to US or UK gallons, cups, fluid ounces and mL with exact factors and worked examples, then check any amount with our volume converter.
Hex to RGB and HSL: How to Convert Color Codes
Convert hex to RGB and HSL instantly, or learn the manual method with worked examples. Our free color converter updates all three formats as you type.
Recipe Scaler: How to Scale a Recipe Up or Down
How to scale a recipe up or down: find the scaling factor, convert awkward amounts, handle eggs and pan sizes, and resize any ingredient list in seconds.
Oven Temperature Conversion: °C, °F and Gas Mark
Oven temperature conversion made simple: Celsius to Fahrenheit formulas, a gas mark chart with fan oven settings, and tips for baking at the right heat.
Baking Pan Size Conversion: How to Swap Pans
Baking pan size conversion explained: calculate pan volumes, find the scaling factor for your recipe, and adjust baking time when you switch pans.
Baker’s Percentage: How to Calculate Dough Hydration
Learn how baker’s percentage works, calculate dough hydration from ingredient weights, and build bread or pizza recipes at any batch size.
Rice to Water Ratio for Every Type of Rice
The right rice to water ratio for white, brown, basmati, jasmine, sushi and wild rice, with a ratio chart, stovetop method and fixes for mushy rice.
JSON Formatter: How to Format and Validate JSON
Format, validate and repair JSON in seconds. Learn the RFC 8259 syntax rules, fix common errors, and pretty-print or minify with our free JSON formatter.
JSON to YAML Converter: Convert Both Ways Online
Convert JSON to YAML and YAML to JSON instantly. See how the formats map, which YAML values change type, and how to avoid errors with our free converter.
JSON to PHP Array: json_decode Guide and Converter
Convert JSON to a PHP array with json_decode() or paste it into our free converter to get clean short array syntax for configs, seeders and tests.
JWT Decoder: How to Decode a JSON Web Token
Decode a JWT to read its header, payload and expiry dates. Learn what each claim means and why decoding isn’t verifying, with our free JWT decoder.
Base64 Encoding Explained: How to Encode and Decode
Learn how Base64 encoding works, why strings end in = or ==, and where it’s used. Encode or decode text instantly with our free Base64 converter.
CSS Box Shadow: Syntax, Examples and Generator
Learn what each CSS box-shadow value does, copy ready-made shadow examples, and build your own with our free CSS box shadow generator and live preview.
Color Contrast Checker: WCAG Contrast Ratios Explained
Check any text and background colors against WCAG 4.5:1, 3:1 and 7:1 contrast ratios. Learn how the ratio is calculated and how to fix colors that fail.
SEO-Friendly URL Slugs: Rules, Examples and Generator
Learn how to write SEO-friendly URL slugs that are short, readable and keyword-rich, then turn any title into a clean slug with our free slug generator.
Lorem Ipsum Generator: What It Is and How to Use It
Generate lorem ipsum paragraphs, sentences or words for mockups, learn where the Latin filler comes from, and avoid placeholder mistakes that ship.
QR Code Generator: How to Make a QR Code for Free
Make a free QR code for a link, Wi-Fi network, email or phone number. Learn what QR codes can hold and how to size and print them so they scan every time.
UUID Generator: Create and Validate UUID v4 Online
Generate up to 50 random UUID v4 values at once and validate any UUID. Learn the RFC 9562 format, the versions, and which one to use for database keys.
Word Counter: How to Count Words and Characters
Count words, characters, sentences and paragraphs as you type with our free word counter, plus typical limits for essays, meta descriptions and posts.
Markdown Previewer: Syntax Guide and Live Preview
Preview Markdown as you type and copy the HTML. Learn CommonMark and GitHub Flavored Markdown syntax for headings, lists, links, tables and code blocks.
Case Converter: Uppercase, Title Case and camelCase
Convert text to uppercase, lowercase, Title Case, camelCase, snake_case or kebab-case in one click with our free case converter. Learn where each fits.
Text Diff Checker: Compare Two Texts Line by Line
Compare two texts and see added, removed and unchanged lines marked instantly. Learn how a text diff works, how to read it, and how to get cleaner results.
Remove Duplicate Lines and Sort Text Online
Remove duplicate lines, trim whitespace, delete empty lines and sort lines A to Z in natural order. Free online tool with real before-and-after examples.
How to Create a Strong Password (Free Generator)
Learn how to create a strong password, what NIST SP 800-63B recommends, and generate a random one in your browser that never reaches our server.
Days Between Dates Calculator: Count Days, Months, Years
Count the days between two dates with our free calculator. Get total days plus years, months and days, with the manual method, leap years and worked examples.
Age Calculator: Your Exact Age in Years, Months and Days
Find your exact age in years, months and days with our free age calculator, plus total days alive, days to your next birthday and how leap-day birthdays work.
Unix Timestamp Converter: Epoch Time to Date and Back
Convert Unix timestamps to readable dates and back with our free epoch converter. Learn how Unix time works, seconds vs. milliseconds and the 2038 problem.
Time Zone Converter: How to Convert Time Across Zones
Convert any time between New York, London, Tokyo and more with our free time zone converter, plus UTC offsets, daylight saving traps and scheduling tips.
Pomodoro Timer: How to Use the Pomodoro Technique
Use our free Pomodoro timer to work in 25-minute focus sessions with short and long breaks. Learn the Pomodoro Technique, interval setups and focus tips.
Year at a Glance Calendar: View Any Year, 1900 to 2100
See any year from 1900 to 2100 at a glance with our free year calendar: color-coded months, weekday and weekend counts, leap years and planning tips.
BMI Calculator: How to Calculate and Read Your BMI
Calculate your BMI in metric or imperial units with our free BMI calculator. See the formula, adult categories, healthy weight by height and what BMI misses.
Navy Body Fat Calculator: Measure Body Fat With a Tape
Estimate your body fat percentage with our free Navy body fat calculator. Learn the U.S. Navy formula, where to measure your neck and waist, and its accuracy.
How Much Water Should I Drink a Day? Calculator Guide
Find out how much water you should drink a day based on your weight and activity level, with our free water intake calculator, official guidelines and tips.