Two's complement of 10
The 8-bit two's complement of 10 is 11110110, the bit pattern that represents -10 (minus 10). Written as a signed 8-bit number, 10 itself is 00001010.
Invert and add 1
Here is the two's complement of 10 at 8 bits, step by step (invert the bits of 10 and add 1):
- Write 10 in 8-bit binary:
00001010. - Invert every bit (the one's complement):
11110101. - Add 1:
11110110.
10 at 4, 8, and 16 bits
| Width | 10 as a signed number | Two's complement of 10 |
|---|---|---|
| 4-bit | — | — |
| 8-bit | 00001010 | 11110110 |
| 16-bit | 0000000000001010 | 1111111111110110 |
A dash means 10 (or its negation) is outside that width's signed range: 4-bit two's complement holds -8 to 7, 8-bit holds -128 to 127, and 16-bit holds -32768 to 32767.
Reading 10 as a binary pattern
The digits of 10 are all 0s and 1s, so "two's complement of 10" often means the 2-bit binary number 10 itself, not the decimal 10. As a signed 2-bit value that pattern is -2. Its two's complement is 10: invert 10 to 01 and add 1.
10 is the most negative 2-bit value (-2), and negating the most negative value overflows back to itself. That is why the two's complement of 10 is again 10.
Convert any number
Two's complement is how computers store signed integers, so one adder can both add and subtract. Read the full two's complement lesson, or convert any value at 8, 16, or 32 bits with the two's complement calculator.
Want to see two's complement do real work? Open the lab and wire a subtractor from an adder and inverters, or follow the free course from a transistor up to an 8-bit CPU.
Open the two's complement calculator →Frequently asked
What is the two's complement of 10?
The 8-bit two's complement of 10 is 11110110, the bit pattern for -10. You get it by writing 10 in binary (00001010), inverting every bit (11110101), then adding 1.
How do you write 10 in two's complement?
10 in 8-bit two's complement is 00001010. Positive numbers are identical to plain binary, so no inverting is needed. At 16 bits it is 0000000000001010.
What is the two's complement of 10 (as binary)?
Reading 10 as a 2-bit binary pattern, its two's complement is 10: invert 10 to 01 and add 1. (10 is the most negative 2-bit value, so negating it overflows back to itself.)