Every web designer who has typed #FF5733 into a color picker has touched hexadecimal without necessarily converting it. Hex (base 16) shows up in programming, memory addresses, error codes, and those six-digit color values — but when you need to actually do arithmetic or understand the magnitude, decimal (base 10) is the system your brain prefers. The conversion weighs each hex digit by a power of 16 based on its position: the rightmost digit counts ones, the next counts sixteens, then 256s, and so on. The letters A through F stand for 10 through 15, which is the only wrinkle.

This page takes your hex value and walks through the classic divide-by-16 method. Type the value in the Hex value (as decimal — enter 0-15 per digit) box — for example 255 for 0xFF — and watch the ÷ 16 box show the quotient at each step while the mod 16 (last digit) box peels off one digit at a time, exactly how long division reveals the place values. The worked example with 26 (0x1A) is worth trying: 26 ÷ 16 gives 1 with remainder 10, and 10 in hex is the letter A. Students working through number-system homework, QA engineers reading hex error codes, and designers who want to know that #FF means 255 (full brightness) all land here for the same reason: hex only makes sense once you can say it in decimal.

With the pre-filled defaults — Hex value (as decimal — enter 0-15 per digit) 255 — the Hexadecimal to Decimal returns ÷ 16 15.9375, mod 16 (last digit) 15. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.