Tech Calculators

These are the calculations that are quick in principle and tedious in practice: working out a usable host range from a CIDR prefix, converting a bitrate into a file size, or deciding what a 16px value becomes in rem at a 62.5% root. Each one shows the intermediate figures, which is what makes them useful for checking a configuration rather than just producing a number.

Networking

The subnet calculator takes an address and a prefix and gives the network address, broadcast address, usable host range, wildcard mask and host count, for every prefix from /0 to /32. The byte converter and download time calculator cover the size-and-speed side, including the bits-versus-bytes confusion that makes a 100 Mbps connection download at about 12 MB/s.

Numbers and bits

The binary calculator, hex calculator and bitwise calculator do arithmetic and AND, OR, XOR, NOT and shift operations in any base, showing the operands in binary so you can see what each bit did.

Screens and media

The px to rem converter and aspect ratio calculator are the two that come up daily in front-end work. The PPI calculator gives a display's real pixel density from its resolution and diagonal, and the video bitrate calculator converts between bitrate, duration and file size in either direction, which is how you hit a size limit without re-encoding twice.