Binary to decimal
Type a value in bin to get it in dec instantly.
255dec
That's about the same as a byte. That needs 8 bits to store.
Convert the other way: dec to bin
What it means
How big is that?
Whole numbers only. Anything after the decimal point is rounded away.
The math
How to convert bin to dec
Base b: each digit is worth b times the one to its right. Gray code = n XOR (n ÷ 2); BCD writes each decimal digit as four bits.
Example: 11111111 bin = 255 dec.
Every unit
Your number in every base
Tables
bin to dec conversion table
| bin | dec |
|---|---|
| 1 bin | 1 dec |
| 10 bin | 2 dec |
| 100 bin | 4 dec |
| 1000 bin | 8 dec |
| 1010 bin | 10 dec |
| 1111 bin | 15 dec |
| 10000 bin | 16 dec |
| 11111 bin | 31 dec |
| 100000 bin | 32 dec |
| 1000000 bin | 64 dec |
| 1100100 bin | 100 dec |
| 10000000 bin | 128 dec |
| 11111111 bin | 255 dec |
| 100000000 bin | 256 dec |
| 1000000000 bin | 512 dec |
| 1111101000 bin | 1,000 dec |
| 10000000000 bin | 1,024 dec |
dec to bin conversion table
| dec | bin |
|---|---|
| 1 dec | 1 bin |
| 2 dec | 10 bin |
| 4 dec | 100 bin |
| 8 dec | 1000 bin |
| 10 dec | 1010 bin |
| 15 dec | 1111 bin |
| 16 dec | 10000 bin |
| 31 dec | 11111 bin |
| 32 dec | 100000 bin |
| 64 dec | 1000000 bin |
| 100 dec | 1100100 bin |
| 128 dec | 10000000 bin |
| 255 dec | 11111111 bin |
| 256 dec | 100000000 bin |
| 512 dec | 1000000000 bin |
| 1,000 dec | 1111101000 bin |
| 1,024 dec | 10000000000 bin |
Quick answers
Quick answers
- How many dec is 1 bin?
- 1 bin is 1 dec.
- How many dec is 1010 bin?
- 1010 bin is 10 dec.
- How many dec is 11111111 bin?
- 11111111 bin is 255 dec.
The units
About these units
Binary (bin)
Base two: only 0 and 1. Every digit is one bit, the smallest unit of computer memory.
Decimal (dec)
Base ten, the everyday counting system, using digits 0 to 9.
Keep going