Mbps to MB/s Converter

This Mbps to MB/s converter turns a connection speed in megabits per second into megabytes per second and back, the conversion behind the most common question about internet speed: why a 100 Mbps plan shows a download running at 12 MB/s. The answer is a factor of eight, because a byte is eight bits, and a network link counts bits while a file counts bytes. Type a speed in Mbps, kbps or Gbps (how plans, speed tests and router pages quote it) or in kB/s, MB/s or GB/s (how a browser's download dialog shows it) and read it in every other unit, including the binary KiB/s, MiB/s and GiB/s that some file-copy dialogs use without saying so. A second box converts data sizes the same way: megabits to megabytes, gigabits to gigabytes, bits to bytes, and decimal GB to the binary GiB Windows Explorer labels "GB". Under every result sit a table of the speed in every unit and a table of common plan speeds in MB/s, with the data each moves per hour and the time 1 GB takes. Everything is arithmetic in your browser; nothing is measured or sent anywhere.

How to use the converter

1. Type the speed and pick its unit. A plan ("300 Mbps"), a speed test or a router status page gives megabits per second: choose Mbps, or Gbps for a gigabit plan. A download dialog, a file copy or a game launcher gives megabytes per second: choose MB/s. If the dialog counts 1,024-byte kilobytes (Windows Explorer's file copy, many torrent clients), choose MiB/s and the result accounts for the 4.9% difference. The seven quick buttons load the speeds people convert most.
2. Read the result. The three figures are the speed in Mbps, in MB/s and in MiB/s; under them, the data that speed moves in a minute, an hour and a day, the time 1 GB takes, then the full table: bps, kbps, Mbps, Gbps, Tbps, B/s, kB/s, MB/s, GB/s, TB/s, KiB/s, MiB/s and GiB/s. The second table lists common plan speeds in MB/s with your speed inserted and highlighted. Copy link to this result gives a link that reopens the page with the same input.
3. Convert a size in the second box. Megabits to megabytes (a 100 Mb figure is 12.5 MB), gigabytes to gigabits (a 1 GB file is 8 Gb, or 8,000 Mb, which is why it takes 80 seconds at 100 Mbps), bytes to bits, and decimal MB or GB to the binary MiB and GiB that Windows reports under the names MB and GB.

The factor of eight

A bit is the smallest unit of data, a single 0 or 1; a byte is eight of them. Network links are described in bits per second because that is what the physical line carries, one bit at a time, so internet plans, Wi-Fi standards, Ethernet ports and speed tests all quote bits: kbps, Mbps, Gbps. Files are stored and counted in bytes, so file sizes, download dialogs, copy progress bars and disk speeds quote bytes: kB, MB, GB and kB/s, MB/s, GB/s. The two systems share their prefixes (kilo 1,000, mega 1,000,000, giga 1,000,000,000) and differ only in the base unit, so the conversion is the same at every scale: MB/s = Mbps ÷ 8 and Mbps = MB/s × 8. 100 Mbps is 12.5 MB/s; 1 Gbps is 125 MB/s; 8 Mbps is 1 MB/s. A 25 Mbps line moves 3.125 MB a second, 187.5 MB a minute and 11.25 GB an hour; a 1 Gbps line moves 125 MB a second and 450 GB an hour. Nothing is lost between the plan's number and the dialog's number; they count different things. The download time calculator runs that arithmetic forward to the time a file takes at a speed.

Mbps, MBps and MB/s: the capital B

The letter case carries the whole difference. A lower-case b is a bit and a capital B is a byte, so Mbps (or Mb/s) is megabits per second and MBps (or MB/s) is megabytes per second, eight times as much. The "ps" and the slash mean the same thing, per second. A search for "mbps to mbps" is nearly always this question: a plan quoted in Mbps against a download shown in MBps. Written out, 100 Mbps = 100 Mb/s = 12.5 MB/s = 12.5 MBps. When a figure appears without the letter at all ("a 100 meg connection", "500 megs") it means megabits, because that is how connections are sold; a figure from a download or a file copy without the letter is almost always megabytes. Marketing material sometimes writes the unit in capitals (MBPS) for a speed that is in megabits, which is the one case where the case rule cannot be trusted: check whether the number describes a connection (bits) or a file transfer (bytes).

MB/s or MiB/s: the 1,024 question

A second gap hides inside the byte units. The decimal prefixes used by storage makers, download pages, macOS and this page make a megabyte 1,000,000 bytes and a gigabyte 1,000,000,000 bytes. Windows Explorer and a number of older tools divide by 1,024 instead and keep the names, so their "MB" is 1,048,576 bytes and their "GB" is 1,073,741,824 bytes, the units the standards call mebibyte (MiB) and gibibyte (GiB). The difference is 4.9% at the megabyte and 7.4% at the gigabyte: 100 Mbps is 12.5 MB/s but 11.92 MiB/s, and 1 Gbps is 125 MB/s but 119.2 MiB/s. A file-copy dialog that counts in 1,024s therefore shows a smaller number than the decimal arithmetic, and the shortfall is the unit, not the line. The converter accepts and shows both so that a figure from either kind of dialog reads correctly, and the size box turns a decimal GB into the GiB that Explorer labels GB: a 4.7 GB file is 4.38 GiB. The video bitrate calculator uses the same pair of units for file sizes.

Common plan speeds in MB/s

The arithmetic figures, with nothing taken off for packet headers, for the speeds plans are sold at. Divide any speed in Mbps by eight for MB/s; multiply by 0.45 for the GB it moves in an hour; divide 8,000 by it for the seconds 1 GB takes.

The other way round, for figures read off a download dialog: 1 MB/s is 8 Mbps, 5 MB/s is 40 Mbps, 10 MB/s is 80 Mbps, 12.5 MB/s is 100 Mbps, 25 MB/s is 200 Mbps, 60 MB/s is 480 Mbps and 125 MB/s is 1,000 Mbps. A download showing 60 MB/s on a 500 Mbps plan is therefore running at 96% of the line, which is as close as packet headers allow.

Network and drive interfaces in both units

The same conversion applies to the ports and cables a file passes through, which are also specified in bits per second. The MB/s column is the line rate divided by eight; where a standard spends part of its line rate on encoding, the usable figure is given after it.

This is why a drive advertised at "6 Gbps" tops out near 550 MB/s and why a USB 3 stick never shows 625 MB/s: the line rate includes the encoding bits, and the usable rate is the line rate times the encoding's efficiency (8/10 for 8b/10b, 128/132 for the newer scheme), then divided by eight.

Why a download shows less than the plan divided by eight

A 100 Mbps plan should, by the arithmetic, show 12.5 MB/s. A real download sits a little below that for reasons that have nothing to do with the units. Every 1,500-byte packet carries 40 bytes of IP and TCP headers and the Ethernet framing adds 38 more, so about 5% of the line rate never reaches the file; that alone turns 12.5 MB/s into 11.9 MB/s, and on a gigabit line turns 125 MB/s into the roughly 117 MB/s (940 Mbps) a speed test reports. A plan's speed is a maximum the line is provisioned for, not a floor; a Wi-Fi link shares its rate between devices and loses it to distance; and the far end sends as fast as it chooses, so a busy server or a per-connection cap is often the real ceiling. A download at a third of the plan's figure divided by eight points at one of those, not at the conversion. The download time calculator lets you take an allowance off the speed before it works out the time.

Megabits to megabytes, and the other size pairs

The size units follow the rate units exactly: bytes = bits ÷ 8 at every prefix. 1 kb (kilobit) is 125 bytes; 1 Mb (megabit) is 125 kB, or 0.125 MB; 1 Gb (gigabit) is 125 MB; 1 Tb is 125 GB. The other way, 1 kB is 8 kb, 1 MB is 8 Mb, 1 GB is 8 Gb (8,000 Mb) and 1 TB is 8 Tb. The pair comes up when a bitrate meets a file size: a video encoded at 8 Mbps for 600 seconds is 4,800 Mb, which is 600 MB, the figure the bitrate calculator returns; a 1 GB file is 8,000 Mb, which at 100 Mbps takes 80 seconds. Mixing in the binary units: 1 MiB is 8.388608 Mb, 1 GiB is 8.589934592 Gb, and 1 GB is 0.9313 GiB. Mobile data allowances are the one place the prefixes get sold the other way round, in bytes (a 10 GB plan), so a 10 GB allowance at 25 Mbps lasts 53 minutes 20 seconds of full-speed use.

What the converter does not do

It does not measure your connection; it has no speed test, and the figure you type is the figure it converts. It does not know which unit a particular app meant when it wrote "MB/s", so if a dialog's number is lower than the decimal figure by 4.9% (or 7.4% at the gigabyte), that app counts in 1,024s and MiB/s is the unit to pick. It does not apply any allowance for packet headers or Wi-Fi; the figures are exact unit conversions, and the download time calculator is the page that takes an allowance into account. And it does not read a speed from a URL or a device.

Frequently asked questions

How many MB/s is 100 Mbps?

12.5 MB/s. A megabit per second is 1,000,000 bits a second, a megabyte is 8,000,000 bits, so divide by eight: 100 Mbps is 12.5 MB/s, 25 Mbps is 3.125 MB/s, 500 Mbps is 62.5 MB/s and 1 Gbps (1,000 Mbps) is 125 MB/s. In the binary MiB/s some file-copy dialogs use, 100 Mbps is 11.92 MiB/s.

Is Mbps the same as MB/s?

No. Mbps (also written Mb/s) counts megabits per second and MB/s (also written MBps) counts megabytes per second; a byte is eight bits, so MB/s is eight times larger. Internet plans, speed tests and router pages quote Mbps because network links move bits; browsers, download managers and file copies show MB/s because files are measured in bytes. A 100 Mbps line is a 12.5 MB/s line; nothing is lost in the gap, the units differ.

How do I convert MB/s to Mbps?

Multiply by eight. A download running at 12.5 MB/s is using 100 Mbps; 25 MB/s is 200 Mbps; 60 MB/s is 480 Mbps; 125 MB/s is 1,000 Mbps, a full gigabit. If the figure came from a dialog that counts 1,024-byte kilobytes, it is MiB/s, and the factor is 8.388608: 12.5 MiB/s is 104.9 Mbps.

What is 1 Gbps in MB/s?

125 MB/s. 1 Gbps is 1,000 Mbps, or 1,000,000,000 bits a second, and a megabyte is 8,000,000 bits, so 1,000,000,000 divided by 8,000,000 is 125. A gigabit line fills a 1 GB file in 8 seconds at that rate. A speed test on a gigabit Ethernet link reports roughly 940 Mbps, about 117 MB/s, because part of the line rate carries packet headers rather than file data.

Why does my 500 Mbps plan download at 60 MB/s?

Because 500 Mbps is 62.5 MB/s, and 60 MB/s is 96% of it, which is as good as a line gets: every 1,500-byte packet carries 40 bytes of IP and TCP headers and the Ethernet framing adds 38 more, so about 5% of a line rate never reaches the file. The dialog is showing bytes, the plan is sold in bits, and the two differ by a factor of eight before any loss. A download well under the plan's figure divided by eight points at the far end, the Wi-Fi link or the plan being a maximum rather than a guarantee.

What is the difference between Mb and MB?

The capital B. Mb is a megabit, 1,000,000 bits; MB is a megabyte, 1,000,000 bytes, which is 8,000,000 bits. The same rule runs through every prefix: kb and kB, Gb and GB, Tb and TB differ by a factor of eight. Network speeds are quoted in bits (Mbps, Gbps) and storage in bytes (MB, GB), which is why a 100 Mbps connection moves 12.5 MB each second and a 1 GB file is 8,000 Mb.

How many Mbps is 1 MB/s?

8 Mbps. One megabyte is 8,000,000 bits, so moving one each second is 8,000,000 bits per second. A 1 MB/s download is therefore an 8 Mbps download; 2 MB/s is 16 Mbps, 5 MB/s is 40 Mbps and 10 MB/s is 80 Mbps.

What is 25 Mbps in MB/s?

3.125 MB/s, so a 25 Mbps connection moves about 3.1 MB a second, 187.5 MB a minute and 11.25 GB an hour, and a 1 GB file takes 5 minutes 20 seconds. Many streaming services name 25 Mbps as the speed for 4K video; the number is the same arithmetic, 25,000,000 bits a second.

What does MBps mean, and is it MB/s?

Yes. MBps, MB/s and megabytes per second are the same unit; Mbps, Mb/s and megabits per second are the other one, eight times smaller. The only difference on the page is the capital B. When a figure is written with a lower-case b or without the letter at all ("100 megs"), it is almost always megabits, because that is how connections are sold.