Numbers & Dates
Calculators for units, dates, numbers, timestamps, Roman numerals and base conversions
All 5 number and date tools run entirely in your browser. Convert units, decode Unix timestamps, calculate date differences, switch between number bases and convert roman numerals — instantly, with zero server calls.
5 tools
Timezone Converter
Convert timestamps and compare times across cities and timezones worldwide
Unit Converter
Convert between length, mass, temperature, volume, speed and 8 more unit types
Number Base Converter
Convert between decimal, binary, hexadecimal, octal and ASCII
Date Calculator
Calculate date differences, add or subtract days, months and years
Roman Numeral Converter
Convert between Arabic numbers and Roman numerals — supports 1 to 3,999 in both directions
All categoriesOther categories
About Numbers & Dates
A complete set of numerical and temporal utilities for developers and engineers. All 5 tools run 100% client-side — no server, no account, no install required. Results update in real time as you type.
Features
- ✓Unit converter — length, weight, temperature, speed, area, volume, data size and pressure with 200+ units
- ✓Timezone converter — epoch seconds/milliseconds ↔ human-readable date/time with timezone and world clock support
- ✓Date calculator — add or subtract days, weeks, months and years; compute the exact difference between two dates
- ✓Number base converter — one-step conversion between decimal, binary, hexadecimal and octal with bit representation
- ✓Roman numeral converter — convert integers (1–3,999,999) to Roman numerals and decode Roman numeral strings back to integers
Common Use Cases
- Convert kilometres to miles or Celsius to Fahrenheit for an internationalised application
- Decode a Unix timestamp in milliseconds from an API response or log file to a readable date
- Calculate the number of days between two dates for a contract, deadline or anniversary
- Convert a memory address or colour code from hexadecimal to decimal for debugging
- Convert chapter numbers or clock-face numerals between Arabic and Roman numeral formats
Frequently Asked Questions
QIs my data sent to a server?
No. All calculations run entirely in your browser using JavaScript. Nothing is transmitted.
QDoes the timestamp converter handle timezones?
Yes. The timestamp converter accepts Unix timestamps in seconds or milliseconds and displays the result in UTC as well as your local browser timezone, with optional manual timezone selection.
QWhat number bases does the base converter support?
Decimal (base 10), binary (base 2), hexadecimal (base 16) and octal (base 8). Enter a value in any base and all others update instantly.
QWhat range does the Roman numeral converter support?
Arabic to Roman for integers 1 to 3,999,999, covering the full extended Roman numeral system including values beyond the standard 1–3,999 range.
See Also
- Unit ConverterConvert length, weight, temperature, speed and 200+ units
- Timezone ConverterConvert timestamps and compare times across 130+ world cities
- Base ConverterConvert between decimal, binary, hex and octal
- Date CalculatorAdd/subtract dates and compute exact date differences
- Roman Numeral ConverterConvert between Arabic integers and Roman numerals