Bit Error Rate

Bit error rate compares how many bits were received incorrectly to how many bits were transmitted in total. It works as a simple ratio because it measures the probability of error on a per-bit basis over a chosen sample of data. A smaller BER means a cleaner link with fewer transmission errors, while a larger BER indicates more noise, interference, or other communication problems.

Use this when evaluating digital communication links such as fiber, radio, Wi‑Fi, or wired networks. It is also useful in testing modems, codecs, or error-correction systems to see how reliably bits are being delivered.

• Using packets or bytes instead of bits in the formula
• Forgetting that BER is a ratio, so the answer is usually a decimal or scientific notation, not a percentage unless converted
• Counting retransmitted or corrected bits the same way as raw received errors without checking how the test was defined