Data transfer rate converter (Mbps to MB/s)

Convert Mbps to MB/s, Gbps to MB/s and kbps to kB/s. Network speeds are quoted in bits per second; file sizes and download meters in bytes.

Drafted with AI writing toolsUpdated Checked examples: 4

A number in the “from” unit, or with its own unit
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Converted value
MB/s
Converted value: 12.5 MB/s
Significant figures: 12; Nearest, ties away from zero
Conversion
100 Mbit/s = 12.5 MB/s
Conversion factor
0.125
Exactness
Exact

100 Mbit/s is exactly 12.5 MB/s. One megabit per second is exactly 0.125 MB/s.

The same amount counted in each unit

Mbit/s100 Mbit/sMB/s12.5 MB/s
100 Mbit/s in every Data transfer unit Rows: 12
UnitValueDefinition
bit per second (bit/s)100,000,000Base unit
kilobit per second (kbit/s)100,0001 kbit/s = 1,000 bit/s, exact
megabit per second (Mbit/s)1001 Mbit/s = 1,000,000 bit/s, exact
gigabit per second (Gbit/s)0.11 Gbit/s = 1,000,000,000 bit/s, exact
terabit per second (Tbit/s)0.00011 Tbit/s = 1,000,000,000,000 bit/s, exact
byte per second (B/s)12,500,0001 B/s = 8 bit/s, exact
kilobyte per second (kB/s)12,5001 kB/s = 8,000 bit/s, exact
megabyte per second (MB/s)12.51 MB/s = 8,000,000 bit/s, exact
gigabyte per second (GB/s)0.01251 GB/s = 8,000,000,000 bit/s, exact
kibibyte per second (KiB/s)12,207.031251 KiB/s = 8,192 bit/s, exact
mebibyte per second (MiB/s)11.920931 MiB/s = 8,388,608 bit/s, exact
gibibyte per second (GiB/s)0.011641531 GiB/s = 8,589,934,592 bit/s, exact
How it's calculated S
  1. Convert megabit per second to bit per second

    100 Mbit/s×1,000,000 bit/sMbit/s=100,000,000 bit/s100\ \text{Mbit/s} \times 1{,}000{,}000\ \tfrac{\text{bit/s}}{\text{Mbit/s}} = 100{,}000{,}000\ \text{bit/s}

    1 Mbit/s = 1,000,000 bit/s, exact

  2. Convert bit per second to megabyte per second

    100,000,000 bit/s÷8,000,000 bit/sMB/s=12.5 MB/s100{,}000{,}000\ \text{bit/s} \div 8{,}000{,}000\ \tfrac{\text{bit/s}}{\text{MB/s}} = 12.5\ \text{MB/s}

    1 MB/s = 8,000,000 bit/s, exact

  3. Combined factor

    1 Mbit/s=1,000,0008,000,000 MB/s=0.125 MB/s1\ \text{Mbit/s} = \frac{1{,}000{,}000}{8{,}000{,}000}\ \text{MB/s} = 0.125\ \text{MB/s}

    Both units are defined exactly and the converted mathematical value has a terminating decimal. A displayed result may still be rounded.

About the data transfer rate converter

Network speeds are quoted in bits per second and file sizes in bytes, and a byte is 8 bits, so megabits per second divide by 8 to give megabytes per second. Each rate unit is a fixed number of bits per second, with decimal prefixes (1 Mbit/s = 10⁶ bit/s) kept apart from binary ones (1 MiB/s = 2²⁰ bytes per second).

The default converts a 100 Mbit/s broadband plan to 12.5 MB/s, the most a download can show in megabytes per second, or 11.92 MiB/s in a program that counts in binary units. A 1 Gbit/s connection tops out at 125 MB/s.

Real transfers run below the line rate because every packet carries headers: in the full-sized Ethernet TCP/IPv4 packet model used here, at most 1,460 of every 1,538 bytes on the wire are data, 94.9%. The download time calculator applies that overhead to a file size.

How to convert Mbps to MB/s

Divide megabits per second by 8, because a byte is 8 bits: 100 Mbps = 12.5 MB/s. Internet plans and Wi-Fi are sold in Mbps (lowercase b, bits), while download managers usually show MB/s (capital B, bytes). Multiply MB/s by 8 to go back: 10 MB/s is 80 Mbps.

Common internet speeds in MB/s

  • 25 Mbps = 3.125 MB/s
  • 50 Mbps = 6.25 MB/s
  • 100 Mbps = 12.5 MB/s
  • 300 Mbps = 37.5 MB/s
  • 500 Mbps = 62.5 MB/s
  • 1 Gbps = 125 MB/s

A gigabit is 1,000 megabits, so 1 Gbps is 1,000,000,000 bits ÷ 8 = 125,000,000 bytes per second. At that rate a 50 GB file takes 400 seconds, or 6 min 40 s, before protocol overhead.

kbps, Mbps and Gbps

Bit-rate prefixes are decimal: 1 Mbps is 1,000 kbps, and 1 Gbps is 1,000 Mbps. Divide by 8 at any prefix to get bytes, so a 128 kbps audio stream is 16 kB/s and a 10 Gbps link tops out at 1.25 GB/s.

MB/s or MiB/s?

Decimal prefixes step by 1,000, so 1 MB/s is 1,000,000 bytes per second. Binary prefixes step by 1,024: 1 MiB/s is 1,048,576 bytes per second, 4.9% more. A program counting in binary units shows a 100 Mbps link as 11.92 MiB/s.

The binary prefixes behind KiB, MiB and GiB come from the IEC and are listed by NIST. Windows labels binary sizes with decimal symbols, writing GB for GiB, so check which kind a speed meter uses.

To turn MiB/s into Mbps, multiply by 8 and by 1.048576: 1 MiB/s is 8.388608 Mbps.

Data rate conversion chart

Repeating decimals are rounded to six places.

ValueFromToConverted rate
100Mbit/sMB/s12.5
1Gbit/sMB/s125
1MiB/sMbit/s8.388608
100Mbit/sMiB/s11.920929
1024KiB/sMiB/s1
10MB/sMbit/s80

Why downloads run below the plan speed

Every packet carries headers. Over Ethernet with TCP/IPv4, at most 1,460 of every 1,538 bytes on the wire are file data, 94.9%, so 100 Mbps delivers at most about 11.9 MB/s. Wi-Fi signal, the far server and other devices cut it further.

A unit conversion gives the line rate with no overhead removed. To estimate how long a file takes, the download time calculator applies this overhead to a file size.

Common mistakes

  • Expecting MB/s to match Mbps. A 100 Mbps plan downloads at most 12.5 MB/s, not 100 MB/s.
  • Mixing kbps and kB/s. 1 kB/s is 8 kbps, and 1 Mbps is 125 kB/s.
  • Writing MBps for Mbps. Case matters: Mbps means megabits per second and MBps megabytes per second.

For the single most common pair, use Mbps to MB/s. File sizes in MB, GB, GiB and TB belong in the data storage converter, and the bandwidth calculator works out how much data a link moves in a set time.

Worked examples

100 Mbit/s in MB/s

Value
100 Mbit/s
From
megabit per second (Mbit/s)
To
megabyte per second (MB/s)
Converted value
12.5 MB/s

Checked against: 100 × 10⁶ bit/s ÷ 8 bit/B ÷ 10⁶ = 12.5

1 Gbit/s in MB/s

Value
1 Gbit/s
From
gigabit per second (Gbit/s)
To
megabyte per second (MB/s)
Converted value
125 MB/s

Checked against: 10⁹ / 8 / 10⁶ = 125

1 MiB/s in Mbit/s

Value
1 MiB/s
From
mebibyte per second (MiB/s)
To
megabit per second (Mbit/s)
Converted value
8.388608 Mbit/s

Checked against: 2²⁰ × 8 / 10⁶ = 8.388608

1 bit/s in kB/s (tiny value)

Value
1 bit/s
From
bit per second (bit/s)
To
kilobyte per second (kB/s)
Converted value
0.000125 kB/s

Checked against: 1 / 8 / 1000 = 0.000125

Questions

How many MB/s is 100 Mbps?

12.5 MB/s. Divide megabits per second by 8, because a byte is 8 bits: 100 ÷ 8 = 12.5. Programs that count in binary units show 11.92 MiB/s for the same speed, and protocol overhead takes about another 5%, so expect around 11.9 MB/s on a wired 100 Mbit/s link.

What is the difference between Mbps and MBps?

Mbps (Mbit/s) is megabits per second; MBps (MB/s) is megabytes per second, 8 times larger. Internet plans and Wi-Fi speeds are sold in Mbps, while browsers and download managers usually show MB/s, so a 50 Mbps plan appears as 6.25 MB/s. The case of the b is the only visible difference.

How fast is 1 Gbps in MB/s?

125 MB/s: 1,000,000,000 bits ÷ 8 = 125,000,000 bytes per second, which is 119.21 MiB/s in binary units. At that rate a 50 GB download takes 400 seconds, 6 min 40 s, before protocol overhead is added.

Why is my download slower than my internet speed?

Part of the gap is units and part is overhead. A plan quoted at 100 Mbit/s is 12.5 MB/s at most, and TCP/IP and Ethernet headers use about 5% of that, leaving about 11.9 MB/s. Wi-Fi signal, the far server and other devices on the connection reduce it further, which this converter does not model.

How many Mbps is 1 MiB/s?

8.388608 Mbit/s. One MiB/s is 1,048,576 bytes per second, and 1,048,576 × 8 = 8,388,608 bits per second. A tool that reports MiB/s therefore shows a number 4.6% lower than the same speed in MB/s.

About this calculator

xto=xfrom×ffromftof=one unit expressed in bit/s\begin{gathered} x_{\text{to}} = x_{\text{from}} \times \dfrac{f_{\text{from}}}{f_{\text{to}}} \\ f = \text{one unit expressed in } \text{bit/s} \end{gathered}

Sources

  1. NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors
  2. NIST Handbook 44, Appendix C — General tables of units of measurement
  3. NIST — Prefixes for binary multiples (IEC 80000-13)

Checked against references

This calculator includes 4 worked examples with independently sourced answers. They run in the test suite, and you can run them here too.

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