Guides

How to Calculate Your GPA (Step by Step) Learn how to calculate your GPA on the 4.0 scale, including weighted GPA by credit hours, with a clear worked example. What Grade Do I Need on My Final Exam? Use a simple formula to find the exact score you need on your final exam to reach your target grade in the class. How to Count Words in an Essay (and Hit Your Word Count) Quick ways to count words and characters in an essay, plus tips for hitting a word count without padding. APA vs. MLA: How to Cite Sources Correctly The difference between APA and MLA citation styles, when to use each, and how to format citations correctly. How to Download a YouTube Thumbnail in HD Download any YouTube video thumbnail in full resolution for free — no software needed. Step-by-step guide. How to Calculate Percentages (Quick Guide) Calculate a percentage of a number, percentage change, and "X is what percent of Y" with simple formulas and examples. How to Convert an Image to PDF (Free, In Your Browser) Turn JPG or PNG images into a PDF for free without uploading your files. Combine multiple images into one PDF. How Long Will My Speech or Video Take? (Words to Time) Estimate how many minutes a speech, script, or video will take based on word count and speaking pace. How to Merge PDF Files for Free (Without Uploading Them) Combine multiple PDFs into one file for free, right in your browser — no software, no uploads, no watermark. How to Calculate BMI (Formula + What It Means) The BMI formula in metric and imperial units, the weight categories, and what BMI does and doesn't tell you. How to Calculate a Tip (15%, 18%, 20%) Calculate a tip and split the bill fast, with the simple percentage trick and a quick reference table. How to Calculate a Discount and Sale Price Work out how much you save and the final price after a percentage discount — plus how to find the original price. How to Create a Strong Password (That You Can Actually Use) What makes a password strong, why length beats complexity, and how to generate and manage passwords safely. How to Calculate Compound Interest (With Examples) The compound interest formula explained simply, with a worked example and why compounding frequency matters. How to Calculate Hours Worked (and Pay) Add up hours from clock-in and clock-out times, subtract breaks, convert to decimal hours, and figure your pay. How to Convert Celsius to Fahrenheit (and Back) The Celsius-to-Fahrenheit formula, the reverse formula, a quick mental shortcut, and a handy reference table. How to Calculate Your Exact Age Work out your age in years, months, and days from your date of birth — and avoid the common off-by-one mistake. How to Calculate Running Pace Calculate your running pace per mile or kilometer, convert pace to speed, and use pace to predict race times. How to Calculate a Monthly Loan Payment The monthly loan payment formula explained, with a worked example for a car or personal loan. How to Calculate Your Grade in a Class Calculate your overall course grade from weighted categories like homework, tests, and the final. How to Read and Write Roman Numerals Learn the Roman numeral symbols, the subtraction rule, and how to convert numbers to Roman numerals and back. How to Make Fancy Text for Instagram & TikTok Bios Make bold, italic and cursive fancy text for your Instagram, TikTok and X bio — and learn why it works almost everywhere. How to Calculate Your TDEE (Maintenance Calories) Calculate your TDEE — the calories you burn per day — using the Mifflin-St Jeor formula, and set targets to lose, maintain or gain. How to Calculate Your One-Rep Max (1RM) Estimate your one-rep max from the weight and reps you lifted, and use percentage-based training to program your lifts. How to Resize an Image Without Losing Quality Resize a photo by pixels or percentage for free in your browser, and learn why shrinking keeps quality but enlarging doesn't. Baking Conversions: Cups to Grams (and Back) Convert cups to grams for flour, sugar, butter and more — and learn why a cup of flour and a cup of sugar weigh differently. How to Calculate Standard Deviation (Step by Step) Calculate standard deviation by hand with a clear example, and understand the difference between population and sample. How Much Water Should You Drink a Day? A simple way to estimate your daily water needs from your body weight and activity — beyond the "8 glasses" rule. Cron Expressions Explained (With Examples) Understand the 5 fields of a cron expression, what *, ranges and steps mean, and common schedule examples. WCAG Color Contrast Explained Understand WCAG contrast ratios, the AA and AAA thresholds, and how to make text readable for everyone. How to Split a Group into Random Teams Fairly divide a list of names into random, balanced teams for class, sports or game night — free and instant. How to Convert JSON to CSV Turn a JSON array of objects into CSV you can open in Excel or Google Sheets — free, in your browser. How to Pay for CDL School (Free & Low-Cost Options) Ways to pay for CDL training: company-sponsored programs, workforce grants, community colleges, and veteran benefits — plus how to avoid predatory contracts. How to Couple a Trailer (and Avoid a High Hitch) Step-by-step guide to coupling a tractor-trailer safely, including how to avoid a high hitch (high-hooking) that leaves the kingpin unlocked. CDL Pre-Trip Inspection: A Simple Walkthrough A plain-English walkthrough of the CDL pre-trip inspection — engine, cab, lights and the walk-around — so you know what to check and why. How to Get Your CDL (Step by Step) The steps to get a commercial driver's license: requirements, the CLP permit, ELDT training, endorsements and the skills test. How to Back Up a Truck and Trailer (Straight, Offset, Alley Dock) Learn to back a tractor-trailer: the steering rule, straight-line backing, the offset back, and the alley dock — plus how to use pull-ups and GOAL. How to Shift a Manual (Non-Synchronized) Truck Learn to double-clutch and float gears in a manual truck: matching RPM, progressive shifting, and downshifting for hills. Hours of Service (HOS) Rules Explained A plain-English guide to the FMCSA hours-of-service rules for truck drivers: the 11-hour, 14-hour, 30-minute break, 60/70-hour limits and the 34-hour restart. Winter Driving Tips for Truckers Safe winter driving tips for CDL drivers: speed, following distance, black ice, chains, braking and when to shut down. CDL Log Books and ELDs Explained How truck driver log books and electronic logging devices (ELDs) work: the four duty statuses, what an ELD records, and who is exempt. How to Summarize an Article or Essay (Free AI Tool) Summarize any article, essay or long document in seconds with a free AI summarizer — plus tips for a good summary. How to Paraphrase Text (Free AI Rewriter) Paraphrase sentences and paragraphs in fresh words while keeping the meaning, using a free AI rewriting tool. How to Check Your Grammar (Free AI Grammar Checker) Fix spelling, grammar and punctuation in any text with a free AI grammar checker — keep your meaning and style.