Mbps to MB/s converter

How to use the Mbps to MB/s converter

Type a number, then pick its unit from the menu. The converter shows:

• The bit or byte twin. Mbps turns into MB/s, megabits into megabytes, and the reverse.
• Every other unit of the same kind. A speed converts to other speeds (kbps, KB/s, Gbps, GB/s). An amount converts to other amounts (megabits, megabytes, gigabits, gigabytes).
• The binary version. A note gives the same figure in MiB, the unit some software uses.
• What it means for a file. At the speed you typed, how long a 1 GB file takes to download.

A worked example. Your speed test says 300 Mbps. Leave the unit on Mbps and the converter shows 37.5 MB/s. In other units that's 300,000 kbps, 37,500 KB/s or 0.3 Gbps. A 1 GB file then downloads in about 27 seconds.

What Mbps means

Mbps stands for megabits per second. It's how much data a connection carries each second, counted in bits. Internet providers, routers and speed tests all quote speeds this way.

The parts of the name:

• M is mega, a million. A megabit is 1,000,000 bits.
• b is bit, the smallest unit of data: a single one or zero.
• ps is per second.

The smaller and bigger steps follow the same pattern. A kilobit is 1,000 bits, so 1,000 kbps is one Mbps. A thousand Mbps is one Gbps, the "gigabit" in gigabit internet.

Megabits against megabytes: the capital B

The two units look alike, and the only difference in writing is the letter case:

A byte is 8 bits. So a megabyte is eight times bigger than a megabit, and the same speed is a number eight times smaller in MB/s.

Networking counts in bits, and storage counts in bytes, so each side kept its own unit. Neither is wrong. They just count in different steps.

The conversion formulas

All of these use decimal units, the way speed tests and internet plans count: a megabyte is 1,000,000 bytes.

• Mbps to MB/s: divide by 8.
• MB/s to Mbps: multiply by 8.
• Gbps to MB/s: multiply by 1,000, then divide by 8. So one Gbps is 125 MB/s.
• kbps to KB/s: divide by 8, the same as for megabits.
• Megabytes to megabits: multiply by 8. A 300 MB file is 2,400 megabits.
• Gigabytes to megabits: multiply by 8,000, since a gigabyte is 1,000 MB.

To check a converted speed against a file, divide the file's size in megabits by the speed in Mbps. That gives seconds, which is all the download time calculator does.

Common Mbps to MB/s conversions

The speeds people convert most, with how long a 1 GB file takes at each one at full speed.

These are ceilings. A real download usually shows a little less, for the reasons below.

Converting amounts of data, not just speeds

The same factor of eight works on sizes. Phone plans, cloud storage and file sizes use bytes, while a few network tools count data in bits.

To go the other way, from bits to bytes, divide by eight. Pick megabits or megabytes in the converter's menu to do it for any value.

MiB and the 1,024 question

Some software counts in binary units instead of decimal ones. A mebibyte (MiB) is 1,048,576 bytes, slightly more than a megabyte. A gibibyte (GiB) is 1,073,741,824 bytes.

That's why the same file or speed can show two numbers. 37.5 MB/s is about 35.8 MiB/s. Some programs show the binary figure but still label it MB.

Apple says storage makers count in decimal. It adds that some older systems report storage in binary, such as iOS 10 and earlier and OS X Leopard and earlier. The difference is about 5% at the megabyte scale and grows with each step up. It never changes the factor of eight between bits and bytes.

The FCC's minimum broadband speed in MB/s

The FCC's minimum benchmark for fixed broadband is 100 Mbps down and 20 Mbps up. Converted, that's 12.5 MB/s down and 2.5 MB/s up.

Upload is usually the smaller number on a home plan. It decides how fast you can send a file, while download decides how fast you receive one. The upload time calculator works out the sending side.

Why your download speed is lower than your internet speed

First, check the units. A browser showing 11 MB/s on a 100 Mbps plan is running at nearly full speed. Once it's converted, the gap mostly disappears.

The rest is real loss, and some of it is unavoidable:

• Packet overhead. RFC 6349, the IETF's guide to testing transfers, puts the best case on a 100 Mbps wired link at 94.9 Mbps. That's about 11.9 MB/s.
• Wi-Fi. Distance from the router and walls in the way can cut the speed well below the plan's.
• The other end. A busy server can't always send as fast as you can receive.

What the MB/s figure means for sending a file

Divide a file's size in MB by your upload speed in MB/s, and you have the seconds it takes to send. SendTheStuff will send up to 5 GB per transfer, with up to 1,000 files in each. SendTheStuff's free version will allow 10 transfers or 20 GB in any rolling 30 days, whichever comes first. A SendTheStuff link will last 14 days. SendTheStuff will let you share it with the Copy, Email, Messages and Share buttons.

Until SendTheStuff launches

For a file too big for email, upload it to a cloud drive you already use and share the link. The guide to the Gmail attachment size limit explains where email stops. Check the wait first with the upload and download time calculators.