Calculators · 8 tools
Online Developer Calculators & Number Converters
Calculators and number converters handle the math developers do every day: hex to decimal, binary conversions, epoch timestamps, subnet masks, file permissions, color formats, and Roman numerals. Every tool runs locally in your browser — no server calls, no tracking, no signup.
Hex to Decimal Converter
Convert hex to decimal or decimal to hex — instant results, free, and fully browser-based.
Epoch & Unix Timestamp Converter
Convert epoch to date or date to epoch timestamp — auto-detects seconds and milliseconds. Free and browser-based.
Binary to Decimal Converter
Convert binary to decimal or decimal to binary — instant results, free, and fully browser-based.
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal — free, instant, and browser-based.
Chmod Calculator
Calculate Unix file permissions interactively — convert between numeric and symbolic notation. Free and browser-based.
IP Subnet Calculator
Calculate subnet mask, network address, broadcast, and host range from any IP and CIDR — free and browser-based.
Color Converter
Convert colors between HEX, RGB, and HSL with live preview — free, instant, and browser-based.
Roman Numeral Converter
Convert between numbers and Roman numerals — supports 1 to 3999. Free, instant, and browser-based.