About the Data Transfer Rate Converter
This data transfer rate converter turns any speed into every common unit at once — bits per second (Kbps, Mbps, Gbps) as internet providers advertise, and bytes per second (kB/s, MB/s, GB/s, MiB/s) as browsers, game launchers and file copy dialogs display. The most common confusion is bits versus bytes: a "100 Mbps" plan downloads at about 12.5 MB/s, because there are 8 bits in a byte.
Use it to check whether your broadband is delivering what you pay for, to compare a Steam or browser download speed with your plan, to size a network link for backups, or to work out whether a NAS or USB drive is the bottleneck. Enter a file size and the tool also estimates the ideal download time at that rate.
Bit-rate units use decimal SI prefixes (1 Mbps = 1,000,000 bits per second), which is how ISPs and network equipment are rated. Binary units such as MiB/s (1,048,576 bytes per second) are included because Windows and many Linux tools report in them. Real downloads are usually around 5–15% slower than the theoretical figure because of protocol overhead and Wi-Fi conditions.
With the default inputs, the megabytes per second is 12.5 MB/s. Change any value above to recalculate instantly.
How to use the data transfer rate converter
- 1Enter the speed you want to convert.
- 2Pick its unit — watch for lower-case b (bits) versus upper-case B (bytes).
- 3Read the equivalent speed in MB/s, Mbps, Gbps and the other units.
- 4Enter a file size to see how long it would take to download at that speed.
Formula and method
The speed is converted to bits per second by multiplying by the unit’s size (for example 1 Mbps = 10⁶ bit/s and 1 MB/s = 8 × 10⁶ bit/s), then divided by the size of each target unit. Decimal prefixes step by 1,000; binary prefixes (KiB, MiB, GiB) step by 1,024, so 1 MiB/s = 8,388,608 bit/s.
Download time divides the file size in bits by the rate in bits per second. It is the ideal minimum — TCP/IP headers, Wi-Fi retransmissions and server limits typically add 5–15% in practice.
- b
- bit (lower-case b) — the unit ISPs advertise
- B
- byte (upper-case B) = 8 bits — the unit file sizes use
- M / Mi
- Mega = 1,000,000; Mebi = 1,048,576
Worked examples
100 Mbps broadband plan
100 Mbps ÷ 8 = 12.5 MB/s. Windows shows about 11.92 MiB/s because it divides by 1,048,576. A 1 GB file is 8,000 megabits, so it takes 8,000 ÷ 100 = 80 seconds at best.
Gigabit fibre and a 50 GB game
1 Gbps is 1,000 Mbps, or 125 MB/s. A 50 GB game is 400 gigabits, so the ideal download takes 400 seconds — about 6 minutes 40 seconds.
A launcher showing 25 MB/s
Multiply bytes by 8 to get bits: 25 MB/s × 8 = 200 Mbps. A 4 GB movie at 25 MB/s takes 4,000 ÷ 25 = 160 seconds.
Frequently asked questions
How do I convert Mbps to MB/s?+
Divide by 8, because a byte has 8 bits. 100 Mbps is 12.5 MB/s, 500 Mbps is 62.5 MB/s and 1,000 Mbps (1 Gbps) is 125 MB/s.
What is the difference between Mbps and MBps?+
Mbps (lower-case b) means megabits per second and is how internet plans are sold. MBps or MB/s (upper-case B) means megabytes per second and is how download managers show progress. 1 MB/s = 8 Mbps.
Why is my download slower than my internet plan?+
Plans are advertised in bits, so the MB/s figure is 8 times smaller. On top of that, protocol overhead, Wi-Fi interference, busy servers and other devices on your network commonly reduce real throughput by 5–15% or more.
What speed is 1 Gbps in MB/s?+
1 Gbps equals 1,000 Mbps or 125 MB/s in decimal units, which is about 119.2 MiB/s in the binary units Windows uses. Real gigabit downloads usually top out around 110–118 MB/s.
Is 1 Mbps equal to 1,000 Kbps or 1,024 Kbps?+
For network speeds it is 1,000 Kbps — telecom rates always use decimal SI prefixes. The 1,024 multiplier only applies to binary units such as KiB and MiB, which some operating systems use for bytes.