Which of the following is the correct unit for upload speed?

• A. 50 MBps
• B. 50 Mbps
• C. 50 GBps
• D. 50 KBps

Answer: (B)

When we talk about internet upload speeds, the rate is measured in bits per second, not bytes per second. The standard unit for consumer speeds is megabits per second, abbreviated Mbps. So 50 Mbps means 50 million bits transmitted every second, which is how internet providers describe upload (and download) speeds.

Other units would describe data in bytes per second. Megabytes per second (MBps) is eight times larger than Mbps, since 1 byte equals 8 bits, so 50 MBps would be 400 Mbps in the same scale. Gigabytes per second (GBps) would be far faster than typical home internet, and kilobytes per second (KBps) is a much slower rate. Because upload speed is conventionally expressed in megabits per second, the correct choice is the unit Mbps.