TAHA Engineering Toolsby TAHA Knowledge Lab

Computer & IT

Download Speed Converter (Mbps ↔ MB/s)

Convert Mbps to MB/s and back, and see the practical speed you might actually get.

Inputs

Leave empty for the theoretical figure only. Enter, for example, the share of your plan speed that a speed test usually shows. This is your estimate.

Result

Megabytes per second (MB/s)
12.5
Megabits per second (Mbps)
100
Mebibytes per second (MiB/s)
11.9209
Time to download 1 GB at the theoretical speed
1.333 min
Working
100 Mbps ÷ 8 = 12.5 MB/s

100 Mbit/s is 12.5 MB/s (11.9209 MiB/s) at most. A 1 GB file would take about 1.333 min.

Educational estimate — check the assumptions below.

About this calculator

Internet plans and network equipment are rated in megabits per second (Mbps, Mb/s), but browsers and download programs usually show megabytes per second (MB/s). Because a byte has eight bits, the number in MB/s is eight times smaller. A “100 Mbps” connection therefore downloads at no more than 12.5 MB/s — which is normal, not a fault.

Formula

MB/s = Mbps ÷ 8    Mbps = MB/s × 8

MiB/s = (Mbps × 10⁶) ÷ (8 × 1 048 576) = Mbps ÷ 8.389

Note the capital and small letters: b = bit, B = byte. Some programs show MiB/s but label it “MB/s”.

Worked example

  • 100 Mbps = 100 ÷ 8 = 12.5 MB/s = 11.92 MiB/s.
  • 1 Gbps fibre = 125 MB/s.
  • A download program showing 6 MB/s = 6 × 8 = 48 Mbps.
  • With a practical share of 90%, 100 Mbps gives about 11.25 MB/s.

Assumptions and limitations

  • The conversion itself is exact. The practical speed is only an estimate based on the share you enter.
  • Real throughput depends on Wi-Fi conditions, the server, network congestion and protocol overhead. A speed test gives the best estimate for your connection.

References

  • IEC 80000-13: bit (b), byte (B) and decimal/binary prefixes.