Computing

Download time, data usage, video and image size, and bitrates.

• Audio Bitrate Calculator Bitrate of uncompressed audio from its sample rate and bit depth, and the average bitrate of any file.
• Audio File Size Calculator The size of an MP3, AAC or other audio file from its bitrate and length.
• Bandwidth Requirement Calculator The bandwidth a group of users needs, with headroom, and the data it carries each month.
• Bits to Bytes Converter Convert kilobits, megabits and gigabits to bytes, megabytes and mebibytes.
• Data Usage Calculator Monthly data use from hours of browsing, music, video and calls, against your allowance.
• Download and Upload Time Calculator How long a file takes to download or upload at a given connection speed.
• File Compression Ratio Calculator The compression ratio and space saved between an original file and its compressed version.
• File Size Calculator Total size of a set of files, in decimal and binary units, and how many fit on a drive.
• Image File Size Calculator The uncompressed size of an image from its pixels and bit depth, and an estimate once compressed.
• Render Time Calculator How long an animation or video takes to render from frames, time per frame and machines.
• Streaming Data Usage Calculator How much data video or music streaming uses per hour and per month at a given bitrate.
• Video Bitrate Calculator The video bitrate that hits a target file size, and how many bits that gives each pixel.
• Video Duration from File Size Calculator How much video fits in a given file size or on a memory card at a given bitrate.
• Video File Size Calculator The size of a video from its bitrate and length.

Aspect ratio, PPI, colour, contrast and CSS units.

• Aspect Ratio Calculator The aspect ratio of any width and height, and the nearest common ratio.
• Aspect Ratio Resize Calculator The new width or height that keeps an image’s shape, or the size that fits or fills a box.
• Colour Contrast Ratio Calculator (WCAG) The WCAG contrast ratio between two colours, with AA and AAA results for normal and large text.
• Colour Converter Convert a colour between HEX, RGB, HSL, HSV and CMYK.
• CSS Unit Converter Convert between px, rem, em, pt, vw, vh, percent and the physical CSS units.
• DPI for Print Calculator The DPI an image will print at for a given size, and the largest print it can make at a target DPI.
• EM to PX Converter Convert em to pixels and back, including what happens when em font sizes are nested.
• Frame Rate and Frame Time Calculator Convert frames per second to milliseconds per frame and back, and count the frames in a clip.
• Golden Ratio Calculator Split a length by the golden ratio, or find the other parts from either section.
• Grid Layout Calculator Column widths for a grid from its container width, column count, gutters and margins.
• HEX to RGB Converter Convert a HEX colour code, with or without alpha, to RGB values.
• Image Scaling Calculator The new size and pixel count of an image scaled by a percentage.
• PPI and Pixel Density Calculator Pixels per inch and dot pitch of a screen from its resolution and diagonal size.
• REM to PX Converter Convert rem to pixels and pixels to rem at any root font size.
• RGB to CMYK Converter Convert RGB values to cyan, magenta, yellow and black percentages.
• RGB to HSL Converter Convert RGB values to hue, saturation and lightness, with HSV and HEX.
• Screen Resolution Calculator Total pixels, megapixels and aspect ratio of a screen resolution, and the raw data rate it needs.
• Type Scale Calculator A modular scale of font sizes in px and rem from a base size and a ratio.
• Viewport Units Calculator Convert between pixels and vw, vh, vmin and vmax at any viewport size.

Subnets, CIDR, IP ranges, throughput and latency.

• Bandwidth-Delay Product Calculator How much data is in flight on a link, and the TCP window needed to keep it full.
• IP Range to CIDR Calculator The smallest set of CIDR blocks that exactly covers a range of IPv4 addresses.
• IPv4 Subnet Calculator: Network, Broadcast and IP Range The network and broadcast addresses, usable IP range, mask and host count for an IPv4 address in CIDR notation.
• IPv6 Subnet Calculator The network, last address, address count and /64 count of an IPv6 prefix, in full and compressed forms.
• Latency and Round-Trip Time Calculator The best-case one-way latency and round-trip time over a distance, with hops and serialisation delay.
• Port Range Calculator How many TCP or UDP ports a range holds, and how it splits between system, user and dynamic ports.
• Subnet Mask Calculator Convert between a subnet mask and its CIDR prefix, with the wildcard mask and host count.
• TCP Throughput Calculator The maximum TCP throughput a connection can reach, given its window, round-trip time, packet loss and link speed.
• Usable Hosts Calculator The smallest IPv4 subnet that holds a given number of hosts, and the host count of nearby prefixes.
• VLSM Subnet Calculator Split an IPv4 network into up to six subnets sized for the hosts each one needs.

RAID, storage arrays, backups and power supplies.

• Backup Window Calculator How long full and incremental backups take, and whether they fit your window.
• PC Power Consumption Cost Calculator What a computer costs to run per year, from its power draw when busy, idle and asleep.
• PC Power Supply Wattage Calculator The power supply size for a PC from the wattages of its parts.
• RAID Capacity Calculator Usable capacity of RAID 0, 1, 5, 6 and 10 arrays from the number and size of disks.
• RAID Fault Tolerance Calculator How many failed disks each RAID level survives, and the chance of surviving a given number.
• Storage Array Usable Space Calculator The space you can really plan to use after hot spares, RAID, file system overhead and free-space reserve.

Unix timestamps, password entropy and token estimates.

• Epoch Converter: Date to Unix Timestamp Convert a date and time in UTC to a Unix epoch timestamp in seconds and milliseconds.
• Password Entropy Calculator The entropy in bits of a randomly generated password or passphrase, from its length and character set sizes.
• Password Strength Calculator How long a random password of a given length and character set would take to guess at a chosen speed.
• Timestamp Difference Calculator The time between two Unix timestamps, in seconds, minutes, hours and days.
• Token Count Estimate Calculator A rough estimate of the AI model tokens in a text, from its characters or words.
• Unix Timestamp Converter Convert a Unix timestamp in seconds or milliseconds to a date and time in UTC.