API Rate Limit Calculator
API quota verdict, safe pace, and time to limit.
Technology and Net
Downloads, data sizes, networks, and security numbers.
Aspect Ratio Calculator
Simplified ratio, orientation, and megapixels from pixels.
Audio File Size Calculator
PCM audio MB, bitrate, and GB hours.
Backup Storage Calculator
Raw storage for the 3-2-1 backup rule from source, copies, and versions.
Base64 Converter
Encode text to Base64 and decode it back, RFC 4648.
Base64 Size Calculator
Turn byte counts into base64 encoded size with overhead bytes and percent.
Color Converter
Hex to RGB, HSL, and CMYK with one input.
Contrast Ratio Calculator
WCAG contrast ratio with AA and AAA verdicts for any color pair.
Data Storage Converter
Convert bits, bytes, KB, MB, GB, TB, and binary KiB, MiB, GiB.
Datacenter PUE Calculator
Datacenter PUE, grade, and overhead kilowatts.
Download Time Calculator
Exact download time from file size and connection speed.
Ebook Storage Calculator
Turn device storage and average book size into books that fit and space left.
Fiber Optic Loss Calculator
Fiber link loss vs power budget with pass, fail, and headroom in dB.
Image File Size Calculator
Megapixels and uncompressed size from pixel dimensions and depth.
IPv6 Subnet Calculator
Split any IPv6 prefix into subnets with counts and child nets.
ISSN Check Calculator
ISSN mod 11 check with spaced format.
Luhn Check Digit Calculator
Luhn check digits and validation for card-style numbers.
Moore's Law Calculator
Transistor counts by year on Moore's pace.
Number Base Converter
Convert between binary, octal, decimal, and hexadecimal.
Password Strength Calculator
Entropy bits and crack time from length and character set.
PoE Budget Calculator
Load, headroom, and verdict for PoE switches.
Print DPI Calculator
Print width, height, and MP from pixels and DPI.
Printer Ink Coverage Calculator
Printer pages and cost per page from rated yield, real coverage, and price.
QR Code Capacity Calculator
Max characters per QR version and error level.
RAID Capacity Calculator
Usable terabytes, efficiency, and fault tolerance from drives and level.
SHA-256 Hash Calculator
SHA-256 digest for any text up to 500 characters.
SMS Parts Calculator
Billed message parts from character count and GSM or Unicode encoding.
Solar Panel Tilt Calculator
Panel tilt, facing, and seasonal pair from latitude.
SSD Lifespan Calculator
SSD years from TBW rating and daily writes.
Streaming Data Usage Calculator
Estimate daily and monthly streaming data from hours watched and video quality.
Subnet Calculator
Netmask, usable hosts, and IP range from address and CIDR.
TV Viewing Distance Calculator
Best couch distance for any TV size in 4K and 1080p.
Unix Timestamp Converter
Seconds since 1970 to UTC date and back, both directions.
UPS Runtime Calculator
Backup minutes from battery and load.
URL Encoder and Decoder
Percent encode text for URLs and decode it back, RFC 3986.
UTF-8 Size Calculator
Byte count of any text in UTF-8, with per character width.
Video File Size Calculator
Exact file size from video length and bitrate.
WiFi Channel Calculator
Best WiFi channels and widths for 2.4, 5, and 6 GHz.
WiFi Range Calculator
Free space WiFi loss from band and meters.
WiFi Speed Split Calculator
Split total Mbps across devices and see HD and 4K stream capacity.
WiFi Standard Calculator
WiFi link speeds and download seconds.