# Developer calculator for Mac, Windows and Linux

Written on 25 October 2026 by Ratio.

The small sums of a working day, in one sheet next to your editor: bits and bytes, subnets, encodings, hashes, and what a model or a server will cost this month.

## Numbers and bits

| 255 in hex | 0xFF |
| --- | --- |
| 0xF0 & 0x3C | 0x30 |
| 300 in u8 | 44 |
| 1 << 4 | 16 |
| chmod 755 | rwxr-xr-x |

## Networks

| 192.168.1.0/24 | 192.168.1.0 – 192.168.1.255 |
| --- | --- |
| 10.0.0.5 in 10.0.0.0/8 | yes |
| /24 mask | 255.255.255.0 |
| 255.255.255.0 in cidr | /24 |

Hover a subnet for its mask, the number of addresses and the usable host range.

## Text, encodings and hashes

Quotes are optional, and a URL with // in it stays whole.

| base64 "hello" | aGVsbG8= |
| --- | --- |
| decode base64 aGVsbG8= | hello |
| urlencode "a b&c" | a%20b%26c |
| md5 abc | 900150983cd24fb0d6963f7d28e17f72 |
| sha256 "abc" | ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad |

`uuid` makes a new random UUID that stays put while you edit.

## Transfers, uptime and costs

`at` divides data by a speed and multiplies a count or a time by its price. `$3/M` is $3 per million.

| 5 GB at 100 Mbps | 6 min 40 s |
| --- | --- |
| 1 TB / 3 h in MB/s | 92.59 MB/s |
| 99.9% uptime | 43 min 50 s |
| 1.2M tokens at $3/M | $3.60 |
| 100 req/s at $0.20/M for 30 days | $51.84 |

## Your own functions

Define one once and it works in every sheet. `forget f` removes it.

| f(x) = x * 1.19 | |
| --- | --- |
| f(100) | 119 |
| area(w, h) = w * h | |
| area(3 m, 4 m) | 12 m² |

[Try Ratio free for 7 days](https://useratio.app/download) · $14.99 once, updates included

## Questions

**Does it run offline?** Yes. Everything on this page is worked out on your computer; only exchange rates and stock prices are fetched.

**Can I hash a file?** No, only the text you type. For files, use shasum or your editor.

**Is there a command line version?** Yes, on the Mac: the ratio command prints the answer to a line, and you can pipe a whole file through it.

Source: https://useratio.app/developer-calculator