bps (bits per second)

bps (bits per second, lowercase b) is the standard unit for data transmission rate. Common multiples: kbps (kilobits, 10³), Mbps (megabits, 10⁶), Gbps (gigabits, 10⁹).

Crucial distinction: bps (bits) is not Bps (bytes). 1 byte = 8 bits, so a 100 Mbps internet connection delivers a theoretical maximum of 12.5 MB/s (megabytes per second). The 8× ratio is a routine source of confusion in ISP marketing — “100 megabit” sounds fast but downloads files at “12.5 megabyte” speeds.

Reference rates:

• Dial-up modem (1990s): 56 kbps
• CD audio: 1411 kbps (uncompressed PCM)
• MP3 (high quality): 320 kbps
• Spotify (Premium): 320 kbps Ogg Vorbis
• YouTube 1080p video: ~5 Mbps
• Netflix 4K HDR: ~25 Mbps
• Modern fiber broadband: 1-10 Gbps
• USB 3.2: 20 Gbps
• Thunderbolt 4: 40 Gbps
• Ethernet datacenter backbones: 100-400 Gbps

For data storage, the byte (or kilobyte, megabyte, etc.) is the standard unit. The convention is essentially: rate in bits, capacity in bytes. Almost every product datasheet follows this.