Guides

Clear, practical explanations of the formulas and ideas behind our tools — with worked examples you can check yourself.

FinanceHow Loan EMI Is Calculated (With Examples)Understand the EMI formula, how each payment splits into principal and interest, and practical ways to pay less interest on any loan.6 min read MathHow to Calculate Percentages: A Simple GuideLearn the three percentage formulas you actually need — percent of a number, percent of a total and percentage change — with worked examples.5 min read HealthWhat Is BMI and What Does Your Number Mean?What Body Mass Index measures, how it is calculated, what the categories mean and why BMI is only one part of the picture.5 min read Date & TimeHow to Count the Days Between Two DatesCount days between dates by hand or with a calculator, handle leap years and month lengths, and decide whether to include the end date.5 min read Text ToolsHow Many Words Is a Page, an Essay or a Blog Post?Typical word counts for pages, essays, blog posts, social posts and meta descriptions, plus how long each takes to read aloud.5 min read Developer ToolsWhat Is Base64 Encoding and When Should You Use It?How Base64 turns bytes into text, why it adds about 33% overhead, URL-safe Base64, and why encoding is not encryption.6 min read Unit ConvertersMetric vs Imperial Units: A Practical Conversion GuideHow the metric and imperial systems differ, the exact conversion factors worth remembering and quick mental-math shortcuts.6 min read