Free Online Calculators & Converters
All calculations run privately in your browser — no data is sent to any server.
Health
- BMI Calculator Calculate your Body Mass Index (BMI) from height and weight. Instantly see your BMI category.
- Age Calculator Calculate your exact age from your date of birth. Shows years, months, and days.
- Days Since Birthday Calculate how many days have passed since your birthday. Also shows years and weeks.
Finance
Unit Conversion
Data Storage
- Byte Converter Convert bytes (B) to KB, MB, GB, TB, PB, or EB. Free online byte storage converter.
- KB Converter Convert kilobytes (KB) to B, MB, GB, TB, PB, or EB. Free online KB storage converter.
- MB Converter Convert megabytes (MB) to KB, GB, TB, PB, or EB. Free online MB storage converter.
- GB Converter Convert gigabytes (GB) to KB, MB, TB, PB, or EB. Free online GB storage converter.
- TB Converter Convert terabytes (TB) to KB, MB, GB, PB, or EB. Free online TB storage converter.
- PB Converter Convert petabytes (PB) to KB, MB, GB, TB, or EB. Free online PB storage converter.
- EB Converter Convert exabytes (EB) to KB, MB, GB, TB, or PB. Free online EB storage converter.
Text
- Text Converter Check for combining characters, toggle case, and convert text to snake_case, kebab-case, SCREAMING_SNAKE_CASE, or PascalCase.
- Combining Character Checker Detect and highlight Unicode combining characters (diacritical marks) in your text. Identify invisible modifiers that may cause encoding issues.
Encoding
- Base64 Encode Encode any file to Base64 or Base64URL. Drag & drop multiple files — output is hidden by default and can be revealed or copied to clipboard.
- Base64URL Encode Encode any file to Base64URL (URL-safe Base64). Uses - and _ instead of + and /, making output safe for URLs and filenames without percent-encoding.
- Base64 Decode Decode Base64 or Base64URL back to the original binary file. Drop text files, paste, or read from clipboard — download the decoded result.
- Base64URL Decode Decode Base64URL (URL-safe Base64) back to the original binary file. Handles - and _ characters used in URL-safe encoding.
All Tools
- BMI Calculator
- Age Calculator
- Tax Calculator
- Discount Calculator
- Tsubo ↔ m² Converter
- ℃ ↔ ℉ Converter
- km/h ↔ m/s Converter
- Byte Converter
- KB Converter
- MB Converter
- GB Converter
- TB Converter
- PB Converter
- EB Converter
- Days Since Birthday
- Text Converter
- Combining Character Checker
- Uppercase Converter
- Lowercase Converter
- Snake Case Converter
- Kebab Case Converter
- SCREAMING_SNAKE_CASE Converter
- PascalCase Converter
- camelCase Converter
- Base64 Encode
- Base64 Decode
- Base64URL Encode
- Base64URL Decode