Skip to content
Convertitive

Hexadecimal to Decimal Converter

FF (hex) = 255 (dec)

Convert hexadecimal numbers to decimal numbers exactly, for any size. Convertitive parses your input as a BigInt — so 64-bit values, 256-bit hex strings, and even larger numbers round-trip without rounding. For quick reference: FF hex = 255 dec, and DEAD hex = 57005 dec.

255
Quick

How to convert hexadecimal numbers to decimal numbers

  1. Enter a value

    Type a hexadecimal integer in the From field. Allowed characters: 0 through 9 and A through F.

  2. Read the decimal result

    The To field updates as you type. For example, the hexadecimal value FF equals 255 in decimal.

  3. Copy or share

    Use the copy button to grab the result. You can change either base from its dropdown without leaving the page.

Reference table

Fifty representative values. Every row is computed exactly by the same BigInt-based converter that powers the widget above.

Hexadecimal (hex)Decimal (dec)
00
11
22
33
44
55
66
77
88
99
A10
B11
C12
D13
E14
F15
1016
1117
1218
1319
1420
1824
1F31
2032
2436
2A42
3048
3250
3F63
4064
64100
7F127
80128
C8200
FF255
100256
1F4500
1FF511
200512
3E81000
3FF1023
4001024
8002048
10004096
20008192
400016384
800032768
FFFF65535
1000065536
1000001048576

Frequently asked questions

How do I convert hexadecimal numbers to decimal numbers?
Enter your hexadecimal value above. Convertitive parses it as an arbitrary-precision integer and reformats it in decimal. The conversion is exact for any size — there's no float rounding.
What is FF in decimal?
FF (hexadecimal) equals 255 in decimal.
Are negative numbers supported?
Yes, with decimal. Two's-complement representations for fixed-width binary/hex are not supported here — the converter treats negative as a sign on the absolute value.
What's the largest number I can convert?
Any size. Convertitive uses JavaScript BigInt, which has no fixed upper bound — 256-bit hex strings, 512-bit and bigger all round-trip exactly.
How many bits does the result take?
An n-digit number in base 16 needs roughly 4.00 × n bits to store. The exact bit length equals ⌈log₂(value + 1)⌉.
Is hex case-sensitive?
No. You can type hex with letters in either case. Output is always uppercase (A–F).
Are conversion factors exact?
Yes. Base conversion is integer-to-integer; there are no factors, no rounding, no precision loss.
Why would I convert hexadecimal numbers to decimal numbers?
Decimal is the human-friendly form. Converting from hexadecimal to decimal makes a value easy to compare, communicate, or paste into spreadsheets and calculators.

About hexadecimal and decimal

Hexadecimal (base 16)

Hexadecimal (base 16) uses digits 0–9 plus the letters A–F to encode the values 10–15. It is the dominant compact notation for binary data: every two hex digits represent exactly one byte. Used universally for memory addresses, color codes (#RRGGBB), and cryptographic hashes.

Decimal (base 10)

Decimal (base 10) is the everyday number system, using the digits 0 through 9. It is the default base for almost all human-facing numbers — from prices to phone numbers to scientific measurements.

Other base converters