Developer Calculator
Convert binary and hex, run bitwise operations, switch between KB and KiB, turn Unix timestamps into dates, and calculate px to rem and aspect ratios, all from one set of tabs.
Number base converter
Bitwise operations
| Operation | Decimal | Hex | Binary |
|---|
Data unit converter
| Unit | Value |
|---|
Unix time ↔ date
px ↔ rem · em
Aspect ratio
How to use
When it helps
While coding you often need to turn a hex color into decimal, check a flag value bit by bit, or find out when a timestamp in a log actually happened. Instead of hunting for a different site each time, the calculations developers reach for most are gathered on one screen.
Base conversion uses BigInt, so numbers beyond 64 bits keep every digit. In the bit view you can click any bit to toggle it and watch the value change, which is handy for permission flags or register values.
The Unix time tab shows your local time, UTC and Korea time side by side, and detects seconds versus milliseconds from the number of digits. For web work there is also a px to rem converter and a screen aspect ratio calculator.
FAQ
How are negative numbers shown in binary?
The base converter shows them with a minus sign (-1010). The bitwise tab shows them as two's complement at the chosen width (8, 16, 32 or 64 bits).
I am not sure if my timestamp is in seconds or milliseconds.
On Auto, values with 12 or more digits are treated as milliseconds and shorter ones as seconds. You can also pick seconds or milliseconds yourself.
What is the difference between KB and KiB?
A KB is 1000 bytes and a KiB is 1024 bytes. Drive makers usually use 1000 while operating systems often use 1024, which is why the same drive can show different sizes.
Can I change the time zone?
Timestamps are shown in your local time, UTC and Korea time, plus ISO 8601. When turning a date into a timestamp, choose whether the date is in your local time, UTC or Korea time.
Are my values sent to a server?
No. Every calculation runs in JavaScript inside your browser.