Programming and tech calculators
Number bases, bitwise operations, hashes, encodings, colour conversion and contrast, subnets and CIDR, UUIDs, RAID capacity, cron expressions and JSON formatting.
17 calculators · 125 checked examples
Numbers and bits
- Binary, hex and decimal converter
Convert numbers between binary, decimal, hex, octal and any base 2–36, including fractions, repeating digits and two's-complement bits for negatives.
- Bitwise calculator (AND, OR, XOR, NOT and shifts)
Bitwise AND, OR, XOR, NOT, NAND, NOR, shifts and rotates on 8- to 64-bit integers, shown in decimal, hex and binary with a bit-by-bit grid.
- Big-O time complexity calculator
Operation counts and running times for O(1), O(log n), O(n), O(n log n), O(n²), O(n³), O(2ⁿ) and O(n!) at your input size, on a log-scale chart.
Text and data
- JSON formatter and validator
Format (pretty-print) or minify JSON and validate it against RFC 8259, with the line and column of any syntax error explained in plain words.
- Base64, URL and HTML encoder and decoder
Encode or decode Base64, URL-safe Base64, URL percent-encoding, HTML entities, hex bytes and Unicode code points, with UTF-8 and UTF-16 byte counts.
- Hash generator and checksum calculator (MD5, SHA-256)
Generate MD5, SHA-1, SHA-256, SHA-512 and CRC-32 hashes of any text, check them against a published checksum, and see the avalanche effect.
- UUID generator and decoder (v4, v7)
Generate reproducible UUID v4 and v7 values from a seed, or validate any UUID or GUID and decode its version, variant and embedded timestamp.
Color
- Color code converter (HEX, RGB, HSL, CMYK, OKLCH)
Convert a color from HEX to RGB, HSL, HSV, CMYK, CIE Lab and OKLCH or back, and find its nearest CSS named color and relative luminance.
- Color contrast checker (WCAG 2.2)
Check the WCAG 2.2 contrast ratio between a text color and its background, with AA and AAA pass or fail for normal text, large text and UI parts.
- Color blindness simulator
How a color looks with protanopia, deuteranopia or tritanopia (red, green or blue color blindness), using the Machado et al. (2009) model.
- Color palette generator (complementary, triadic, analogous)
Generate complementary, analogous, triadic, split-complementary, tetradic or monochromatic color palettes from one base color, with HEX codes.
Display and media
Network and storage
- Subnet calculator (IPv4 and IPv6 CIDR)
Find the network address, broadcast, usable host range and host count of any IPv4 or IPv6 CIDR block, with netmask, wildcard and equal subnets.
- Bandwidth and download time calculator
Download or upload time for a file at a given speed, the data a link moves in a set time, and a website's monthly bandwidth from page views.
- RAID calculator (RAID 0, 1, 5, 6 and 10)
Calculate usable RAID capacity, parity or mirror overhead and how many drive failures RAID 0, 1, 5, 6 and 10 survive, in TB and the TiB Windows shows.
Security
Scheduling
Choosing a calculator: Code
How do I convert binary to hexadecimal?
Use the number base converter and state the base of the number you enter. For bitwise operations, also set the width and whether numbers are signed, because both change the result.
How do I work out a subnet from a CIDR prefix?
Use the subnet and CIDR calculator, which works from the prefix length as well as the address. Try a small example you already know first to confirm the settings.
How do I check color contrast for accessibility?
The WCAG contrast checker gives the contrast ratio between a text color and its background, with AA and AAA results. Real interfaces also depend on text size, transparency, focus states and background, so check the finished screen too.