A Calculator That Speaks Hex

Four bases, no mode switching

Most programmer calculators make base a mode: pick hex, get hex. CalcBoard shows binary, octal, decimal and hexadecimal at the same time, all updating as you type, with binary grouped into nibbles so you can read the bit pattern at a glance. Converting stops being an operation and becomes something you just look at.

What's on the keypad

• Hex digits A–F as real keys, not a shifted layer.
• Bitwise AND, OR, XOR, NOT and left/right shifts.
• Arbitrary-size integers. Values beyond 64 bits fall back to big integers rather than silently overflowing — the failure mode of nearly every browser-based tool, including our own free one.
• Full expression editing with parentheses, an inline cursor, and 50 levels of undo.

The second panel is the point

Debugging rarely stays in one base. You are checking a mask in hex while working out a buffer size in decimal, or reading a permission bitfield while calculating how many entries fit in a page. One calculator means clearing the first number to get the second.

CalcBoard runs up to eight panels at once, each in its own mode — programmer on the left, basic or scientific on the right — with a shared value tray for moving results between them. The free Developer layout is a Premium preset; two panels of any kind are free.

Exact decimal arithmetic, which matters more than it sounds

CalcBoard computes in arbitrary-precision decimal rather than IEEE-754 doubles, so 0.1 + 0.2 is exactly 0.3. If you have ever debugged a currency rounding bug, you already know why that is the right default — and why your language does not do it.

Data sizes done right

The converter keeps decimal (KB, MB, GB) and binary (KiB, MiB, GiB) units separate rather than pretending they are the same, which is the 1 TB drive shows as 931 GB problem in a nutshell.

Frequently Asked Questions