Even Parity Calculator
Enter a decimal number and word size to see its binary form, count of 1-bits, current parity, and the even or odd parity bit used in serial communication and memory error detection.
Word size
Append this bit to make the total count of 1-bits even
- 1
1-bits in the word
5 - 2
Parity check
5 mod 2 = 10 = already even; 1 = odd — a correction bit of 1 is needed. - 3
Even parity bit
1Append to the data word so the total 1-bit count is even.
How does this calculator work?
The even parity bit is 0 when the binary word already has an even number of 1-bits, or 1 when the count is odd — keeping the total always even. Appended to data words in UART, RAM, and simple network frames, it lets the receiver detect single-bit transmission errors. Odd parity is its complement.
Formula
How this is calculated
A parity bit is a single extra bit appended to a binary word so that the receiver of a data transmission can detect errors. With even parity the goal is to keep the total number of 1-bits — across the data word and the parity bit together — always even. If the word already has an even count of 1-bits the parity bit is 0; if the count is odd the parity bit is 1, making the total even. The receiver counts 1-bits in every received frame: a total that is not even signals that at least one bit was corrupted.
This calculator converts your decimal input to its binary representation padded to the chosen word size, counts the 1-bits, then derives both the even and odd parity bits so you can use whichever scheme your protocol requires. Common uses include UART serial communication frames, older RAM parity checking, and simple network headers. The binary representation with the parity bit already appended is shown for direct use.
One parity bit only catches an odd number of simultaneous bit-flips — one, three, five, etc. Two simultaneous flips cancel out and go undetected. For stronger error detection or correction use CRC codes, Hamming codes, or Reed-Solomon, which this calculator does not cover.
Frequently asked questions
Even parity is an error-detection scheme where a parity bit is appended to each data word so that the total number of 1-bits in the word plus the parity bit is always even. If the data already contains an even number of 1s the parity bit is 0; if odd, it is 1.
Even parity keeps the total count of 1-bits (data + parity) even; odd parity keeps it odd. The even parity bit is always the bitwise complement of the odd parity bit. Both detect a single flipped bit; the sender and receiver must agree on which scheme to use.
A single parity bit only detects an odd number of bit errors (1, 3, 5 …). If exactly two bits flip simultaneously their errors cancel out and the parity remains correct, so the error goes undetected. Protocols that need stronger protection use multi-bit schemes such as Hamming or CRC codes.
TG we-Calculate Editorial Team. (2026). Even Parity Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/even-parity-calculator
TG we-Calculate Editorial Team. "Even Parity Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/even-parity-calculator.
TG we-Calculate Editorial Team, "Even Parity Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/even-parity-calculator
@misc{wecalculate_even_parity_calculator, title = {Even Parity Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/even-parity-calculator}}, year = {2026}, note = {TG we-Calculate} }
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