Why Internet Speed Units Are Confusing

Internet speeds are measured in megabits per second (Mbps), but file sizes are measured in megabytes (MB). The difference between a lowercase "b" and uppercase "B" represents an 8x difference in value — and ISPs always advertise in the smaller unit.

Bits vs Bytes

  • 1 byte = 8 bits
  • 1 Mbps (megabit per second) = 1,000,000 bits per second
  • 1 MBps (megabyte per second) = 8,000,000 bits per second

So a 100 Mbps connection can transfer approximately 12.5 MB per second (100 ÷ 8 = 12.5).

Complete Unit Reference

UnitFull NameEquivalent
1 KbpsKilobit per second1,000 bits/s
1 MbpsMegabit per second1,000 Kbps
1 GbpsGigabit per second1,000 Mbps
1 KBpsKilobyte per second8 Kbps
1 MBpsMegabyte per second8 Mbps
1 GBpsGigabyte per second8 Gbps

Real-World Download Time Examples

File Size10 Mbps100 Mbps1 Gbps
1 MB (photo)0.8s0.08sinstant
100 MB (app)80s8s0.8s
1 GB (movie)13 min80s8s
50 GB (game)11 hrs67 min7 min

Why ISPs Use Mbps Instead of MBps

ISPs advertise in megabits (Mbps) because the numbers are 8x larger, making plans sound faster. A "100 Mbps" plan sounds more impressive than "12.5 MBps" even though they're the same speed. This is legal and standard practice — just something to be aware of when comparing plans.

How to Convert Mbps to MBps

Divide by 8: Mbps ÷ 8 = MBps

  • 10 Mbps = 1.25 MBps
  • 50 Mbps = 6.25 MBps
  • 100 Mbps = 12.5 MBps
  • 500 Mbps = 62.5 MBps
  • 1 Gbps = 125 MBps

What Speed Do You Actually Need?

Now that you understand the units, run our speed test to see your actual Mbps. Then divide by 8 to understand your real-world download speed in MBps — the number you'll see in your browser's download manager.