Convert hexadecimal to decimal (hex to decimal) as you type, with every step shown. This free online converter gives exact results for numbers of any size, and nothing you type leaves your browser.
1 Enter your value
From
To
0x
Examples
2 Your answer
Decimal
dec
Show in other bases
Tap any value to copy it.
See the working
Guide
How it works
Three steps, whether you are reading a memory address, a bit flag or a byte value.
1
Choose what to convert
Pick what you have and what you want: decimal, hexadecimal, binary or octal.
2
Type or paste a value
Write it however you like: 65,535, 0xFF, FFh, with commas, spaces or underscores.
3
Read the answer
It appears as you type, in every other base, with the working shown.
The formulas
A digit's value depends on its position. Every answer here uses one of these rules:
Hexadecimal to decimal
decimal = Σ digit × 16position
0x1A3 is 1 × 256 + 10 × 16 + 3 × 1 = 419, so the answer checks out.
Decimal to hexadecimal
divide by 16, keep the remainders
419 ÷ 16 = 26 r 3, 26 ÷ 16 = 1 r 10 (A), 1 ÷ 16 = 0 r 1, so 419 is 0x1A3.
Hexadecimal to binary
each hexadecimal digit = 4 binary bits
0x1A3 is 1 → 0001, A → 1010, 3 → 0011, so 0x1A3 is 0001 1010 0011.
Decimal to hexadecimal digit chart
The decimal values 0 to 15 are the single hexadecimal digits 0 to F. Click one to add it to the converter.
All conversions
Decimal, hexadecimal, binary and octal converter
One free tool for every direction. Use it as a decimal to hexadecimal converter, convert decimal to binary or octal, or work backwards as a hexadecimal to decimal converter that turns 0x to decimal values. It also converts hexadecimal to binary, binary to hexadecimal and octal to decimal, so it works as a full number base converter and hexadecimal calculator. Pick a conversion to start.
Use this hexadecimal to decimal table as a quick hexadecimal to decimal chart for common values, from 0 to 65,535.
Hexadecimal
Decimal
0
0
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
A
10
B
11
C
12
D
13
E
14
F
15
10
16
20
32
40
64
64
100
7F
127
80
128
FF
255
100
256
200
512
3E8
1,000
400
1,024
1000
4,096
FFFF
65,535
Help
Questions
Quick answers to what people most often ask about hexadecimal, decimal and binary.
01How do I convert hexadecimal to decimal?
To convert hexadecimal to decimal, number the digits from the right, starting at 0. Multiply each digit by 16 raised to the power of its position. Add the results together to get the decimal number. Remember that A to F stand for 10 to 15.
02What is FF in decimal?
0xFF in hexadecimal is 255 in decimal. Type FF into the converter above to see every step.
03What is 400 in decimal?
0x400 in hexadecimal is 1,024 in decimal.
04What is 10 in decimal?
0x10 in hexadecimal is 16 in decimal. That is why 0x10 means sixteen, not ten.
05What is FFFF in decimal?
0xFFFF in hexadecimal is 65,535 in decimal. It is the largest unsigned 16-bit number.
06What is 7FFFFFFF in decimal?
0x7FFFFFFF in hexadecimal is 2,147,483,647 in decimal. It is the largest signed 32-bit integer.
07Why does hexadecimal use the letters A to F?
Base 16 needs sixteen single-digit symbols, but there are only ten digits, 0 to 9. The letters A to F stand for 10 to 15, so A = 10 and F = 15, and 0xFF is 15 × 16 + 15 = 255.
08How do I convert hexadecimal to decimal in Excel?
Use the HEX2DEC function: =HEX2DEC("FF") returns 255. It works the same way in Google Sheets. These functions only handle up to 10 input characters, and the binary ones only −512 to 511, so use this converter for larger numbers.
09How do I convert hexadecimal to decimal in Python or JavaScript?
In Python, int('FF', 16) returns 255. In JavaScript, parseInt('FF', 16) returns 255. Python handles any size; in JavaScript use BigInt for numbers above 2⁵³.
10Does the converter use two’s complement for negative numbers?
No. It keeps the minus sign, so −255 is −0xFF, −0b11111111 and −0o377. Computers usually store negative numbers in two’s complement, where the pattern depends on the width: −1 is 1111 1111 (0xFF) in 8 bits and 0xFFFF in 16 bits. To read a signed value whose top bit is set, subtract 2ⁿ: 0xFF as a signed 8-bit number is 255 − 256 = −1.
11Can I convert hexadecimal numbers with a fractional part?
The converter works with whole numbers. By hand, convert the fractional part by multiplying it by the target base again and again and keeping the whole-number part each time. For example, 0.5 × 16 = 8, so 0.5 is 0x0.8 in hexadecimal, 0b0.1 in binary and 0o0.4 in octal.
12How many hexadecimal digits are in a byte?
Two. One hexadecimal digit is 4 bits, so a byte (8 bits) is two digits, from 00 to FF (0 to 255). A 16-bit number is 4 digits, a 32-bit number is 8 and a 64-bit number is 16.
13How do I convert a hex colour code to RGB?
Split the six digits into three pairs and convert each pair to decimal: #FF8000 is FF = 255 red, 80 = 128 green and 00 = 0 blue, so it is rgb(255, 128, 0).
14Is there a limit to how big a hexadecimal number can be?
No. The converter uses exact whole-number arithmetic, so 64-bit, 128-bit and longer hexadecimal values convert to decimal with every digit correct, with no rounding.
15What does “hex to dec” mean?
“hex to dec” is short for hexadecimal to decimal, which means going from base 16 to base 10: a number written in base 16 is rewritten in base 10. For example, 0xFF becomes 255.
16Does this hexadecimal to decimal calculator show the working?
Yes. It converts hexadecimal to decimal with steps: open “See the working” under the answer to see each digit multiplied by its power of 16. Every answer is also shown in decimal, hexadecimal, binary and octal at once.
17Is this hexadecimal to decimal converter free?
Yes. It is free with no sign-up, works online on phones, tablets and computers, and every hexadecimal to decimal conversion runs in your browser, so nothing you type is sent anywhere.