Mbps to MB/s Converter

Your broadband is sold in Mbps, but the download crawling across your screen is measured in MB/s — and the second number looks eight times smaller. That gap catches out almost everyone at least once. Our mbps to mb/s converter settles it instantly: type your speed in Mbps to see it in MB/s, or type the MB/s your download is showing to check it against the package you pay for. Both boxes update live, because this is a two-way converter, not a one-way calculator.

If you have never measured your connection at all, start with the free speed test on the Speed Test UK homepage. It reports your speed in Mbps — the figure every UK provider uses — and then you can convert it here to see what your downloads should look like in MB/s.

How to Use This Mbps to MB/s Converter

• Step 1: Type in either box. Enter your broadband speed in the Mbps box, or the download speed you can see in the MB/s box. The other box fills itself in.
• Step 2: Read the full breakdown. Underneath, the converter shows your speed in Kbps, Gbps, KB/s, GB/s and MiB/s (the unit Windows actually uses), plus how much data you could download in an hour.
• Step 3: Check the Steam example. The panel under the converter applies your speed to a typical big game download, so you can see exactly what the conversion means in practice.
• Step 4: Compare with the table. The conversion table covers the speeds UK packages really sell — including 36 and 67 Mbps part-fibre tiers that most converters skip.

Bits vs Bytes: The Whole Explanation in One Minute

A bit is the smallest unit of data: a single 0 or 1. A byte is a group of 8 bits — enough to store one character of text. Broadband speeds are measured in bits per second, written Mbps (megabits per second, small “b”). File sizes and download speeds are measured in bytes, written MB/s (megabytes per second, capital “B”). That one letter — b versus B — is the entire source of the confusion.

Because a byte holds 8 bits, the conversion is always the same:

MB/s = Mbps ÷ 8  and  Mbps = MB/s × 8

So a 100 Mbps connection can download at a maximum of 12.5 MB/s. When your browser reports 12 MB/s on a 100 Mbps package, your broadband is not underperforming — it is delivering almost exactly what you pay for, just expressed in different units. Providers are not cheating with the bigger number, either: bits per second has been the standard way to describe network speeds for decades, and Ofcom’s advertising rules require the speeds providers quote to be available to at least half of their customers at peak times. The problem is simply that the two industries — networks and computers — settled on different units.

Mbps to MB/s Conversion Table for UK Broadband Speeds

Notice how the table explains two everyday puzzles. First, why a “gigabit” connection never shows 1,000 of anything in a download window: its ceiling is 125 MB/s. Second, why part-fibre downloads feel slow next to the headline: a 67 Mbps line tops out at about 8.4 MB/s, so a 50 GB game is always going to take well over an hour and a half on it, however well the line is working.

Worked Example: What Your Steam Download Should Really Show

Say you are on a 67 Mbps package — BT Fibre 2, Sky Superfast or an equivalent — and you buy a game on Steam that weighs in at 85 GB. Steam displays download speeds in MB/s, so the fastest you should ever see is 67 ÷ 8 = 8.38 MB/s. In practice you will see it hover between about 7 and 8.3 MB/s, because a slice of the line goes on overheads. At a steady 8 MB/s, the 85 GB download takes roughly 2 hours 57 minutes. Steam’s graph, sitting stubbornly under 10 MB/s, looks broken only if you expected it to say 67.

Now compare a full fibre line at 500 Mbps. Steam’s ceiling becomes 62.5 MB/s, and the same 85 GB game lands in about 23 minutes. That difference — not the headline number — is what an upgrade actually buys a gaming household. If you are trying to decide whether the jump is worth it for your home, our guide to the broadband speed you need works through the decision household by household, and our broadband speed test guide shows you how to measure the line you already have, properly wired, before you spend anything.

Kbps, Gbps and MiB/s: The Other Units in the Converter

The main event is Mbps and MB/s, but you will meet four relatives:

• Kbps (kilobits per second): a thousand bits per second. Mostly history now in the UK — old dial-up and early ADSL were sold in Kbps — but audio streams and some sensors still use it. 1 Mbps = 1,000 Kbps.
• Gbps (gigabits per second): a thousand Mbps. Full fibre packages of 900 Mbps and above are often described as “gigabit” broadband. 1 Gbps = 125 MB/s.
• KB/s and GB/s: the byte versions at the edges — KB/s for slow transfers, GB/s for very fast local networks and storage. The converter shows both so a figure in any unit can be checked.
• MiB/s (mebibytes per second): the quiet troublemaker. Windows measures file sizes in binary units — 1 MiB = 1,048,576 bytes rather than a round million — but labels them “MB”. So the same download can read as 12.5 MB/s in one program and about 11.9 MiB/s in Windows, with nothing at all wrong. Providers, Steam and this converter all use decimal units, which is why our figures may differ slightly from what Windows shows you.

When Your MB/s Is Much Lower Than Mbps ÷ 8

A small gap is normal: seeing 11–12 MB/s on a 100 Mbps line is healthy. A large gap — say your downloads sit at 4 MB/s on a package that should give 12.5 — means something real is limiting you, and it is worth working through the usual suspects:

• Wi-Fi losses. The converted figure is what the line can do. A laptop two rooms away from the router may receive half of it. Test wired; if wired downloads match the conversion and wireless ones do not, the line is fine and the Wi-Fi needs the attention.
• A busy house. Every stream and download shares the same MB/s. Two 4K streams can take 6 MB/s between them before your download gets anything.
• The server’s limit. Some services cap speeds per connection, and all of them slow down on their busiest nights. If one service is slow and everything else matches the conversion, the problem is at their end.
• Peak-time sag. Between roughly 8pm and 10pm, UK networks are at their busiest. Ofcom’s rules only require advertised speeds to be achievable by at least half of customers at peak — your own line’s minimum guaranteed speed, quoted when you joined, is the figure that protects you. Ofcom sets out the code on its broadband speeds code pages.
• Delay, not capacity. Sometimes downloads are fine and it is responsiveness that feels broken — pages hesitate, games judder. That is latency, a different measurement entirely. Our ping tester measures it in milliseconds.

If a wired speed test repeatedly lands far below the speed on your bill, keep a note of results over several days. Providers take a dated log far more seriously than an impression, and Thinkbroadband publishes independent data on what networks typically deliver. If you are simply outgrowing your package, checking whether full fibre has arrived at your address via the Openreach fibre checker is the natural next step, and our guide to good internet speeds will help you judge how much is enough.

Converting in Your Head: Three Shortcuts Worth Knowing

You will not always have this page open, so here are the shortcuts regular users rely on. First, divide by 8, or near enough, divide by 10 and add a quarter: 80 Mbps ÷ 10 is 8, plus a quarter (2) gives 10 MB/s — close to the exact 10. Second, memorise the anchor points: 100 Mbps is 12.5 MB/s, 500 Mbps is 62.5 MB/s, and gigabit is 125 MB/s; most UK packages sit near one of those three. Third, work backwards from the file: a download finishing 1 GB a minute is running at about 16.7 MB/s, which means roughly 133 Mbps of your line is in use.

The reverse shortcut matters when a program quotes you MB/s and you want to know how much of your line it is eating. Multiply the MB/s by 8. A video call uploading at 2 MB/s is using 16 Mbps — comfortable on full fibre, but most of the upload on a part-fibre package, which is exactly why calls can wobble when someone starts a cloud backup in the next room. Once you can flip between the two units without thinking, broadband adverts, speed tests and download windows all start telling you the same story.

Frequently Asked Questions

How many MB/s is 100 Mbps?

12.5 MB/s. Divide any Mbps figure by 8: 100 ÷ 8 = 12.5. In practice you will see roughly 11–12 MB/s in a browser or Steam once normal overheads are taken off, and a 1 GB file will take about 1 minute 20 seconds.

Why is my download speed in MB/s so much lower than my broadband speed?

Because the units differ by a factor of 8. Broadband is sold in megabits per second; downloads are displayed in megabytes per second, and there are 8 bits in a byte. If your MB/s figure is close to your Mbps divided by 8, your connection is working as expected. If it is far below that even on a wired connection, treat it as a possible fault and test again at different times of day.

Is 25 MB/s the same as 200 Mbps?

Yes. Multiply MB/s by 8 to go the other way: 25 × 8 = 200 Mbps. That is the sort of line sold as Full Fibre 200 or a Virgin Media M250-class package, and it will download a 10 GB file in about 6 minutes 40 seconds.

What is the difference between MB/s and MiB/s?

An MB is 1,000,000 bytes (decimal); a MiB is 1,048,576 bytes (binary) — about 4.9% more. Windows uses binary units but calls them MB, so its figures read slightly lower than decimal tools like this converter for exactly the same transfer. Neither is wrong; they are measuring with slightly different rulers.

How fast is 1 Gbps in MB/s?

125 MB/s. Gigabit broadband (1,000 Mbps) can move about 125 megabytes every second, which is roughly 450 GB in an hour. A 100 GB game that takes over 3 hours on a 67 Mbps line lands in about 13–14 minutes.

Can I convert my upload speed the same way?

Yes — upload speeds are also quoted in Mbps, and the same divide-by-8 rule applies when you watch an upload progress bar in MB/s. UK upload speeds are much lower than download speeds on most packages (often 10–20 Mbps on part fibre, giving roughly 1.25–2.5 MB/s), which is why sending large videos takes so long.

Convert Your Speed, Then Check It for Real

Now the two numbers on your screen should agree with each other. Convert your package speed above, then run a quick test on the Speed Test UK homepage and convert the result: if the MB/s you actually get is close to the MB/s you pay for, your broadband is doing its job — whatever the progress bar made you suspect.