Practical, in-depth articles that explain the concepts behind our tools — from loan mathematics and investing to password security and everyday mental math. Each guide pairs with a free tool so you can put what you learn into practice immediately.
Understand exactly how banks calculate your monthly EMI, what reducing-balance interest means, and how tenure and rate changes affect your total repayment.
Read the guideA practical comparison of systematic investment plans and lump-sum investing — how rupee-cost averaging works, when each approach wins, and what the math actually says.
Read the guideSee why compounding is called the eighth wonder of the world, how the rule of 72 works, and why a 25-year-old investing less can retire richer than a 35-year-old investing more.
Read the guideA plain-language guide to how GST works in India — the four main tax slabs, how CGST and SGST split, and how to correctly extract tax from an inclusive price.
Read the guideHow Body Mass Index is calculated, what the WHO categories mean, and why athletes, older adults, and some populations need to interpret their BMI with caution.
Read the guidePractical mental math shortcuts for the percentage problems you meet every day — sale discounts, restaurant tips, percentage change, and the reversibility trick.
Read the guideThe essential conversions between metric and imperial units — with memorable benchmarks for length, weight, and temperature that make estimates easy without a calculator.
Read the guideWhat actually makes a password strong, why long random passwords beat clever substitutions, and how password managers and passkeys change the game.
Read the guideResearch-backed length targets for essays, blog posts, emails, social media, and video scripts — and why the right length is about reader attention, not arbitrary rules.
Read the guideWhat JSON is, the six data types it supports, the strict syntax rules that trip up beginners, and how JSON differs from JavaScript objects, XML, and YAML.
Read the guide