Guides
Short, practical guides that pair with our most-used tool categories. Each includes examples, FAQs, and links to the relevant tools.
We wrote these so you can quickly understand the concepts and then use our free tools to do the math or conversion yourself—no account required.
Percentages and Discounts: A Practical Guide
How to work with percentages, sale prices, and discounts. With examples and links to free calculators.
2 related tools · Math & Numbers
Mortgage and Loan Basics: What You Need to Know
How mortgages and loans work, what affects your payment, and how to estimate it. With links to our calculators.
3 related tools · Money & Finance
Unit Conversion Basics: Length, Weight, and Temperature
How to convert between metric and imperial units. Practical examples and links to our converters.
3 related tools · Unit Converters
Word Counts and Text Tools: Hit Your Limits and Clean Copy
How to meet word limits, count characters, and use simple text tools. With links to our word counter and related utilities.
3 related tools · Text Tools
BMI and Health Metrics: What They Mean and When to Use Them
What BMI is, how to interpret it, and when to use BMR/TDEE. With links to our calculators.
2 related tools · Calculators
Hashes and Encoding: When to Use Hash, Base64, and URL Encode
What hashes and encoding are for, when to use each, and how to use our free hash, Base64, and URL encode/decode tools.
3 related tools · Developer Tools
Using Date and Time Tools: Epoch, Time Zones, and Conversions
How to work with Unix timestamps, time zones, and date differences. With links to our epoch and timezone converters.
2 related tools · Date & Time
Color Contrast and Accessibility: WCAG Basics
Why contrast matters for readability and accessibility, how WCAG levels work, and how to use our color and contrast tools.
2 related tools · Color Tools