Checking a broadband speed
A 500 Mbps plan tops out at 62.5 MB/s. A browser download showing 55 MB/s on that line is running at about 88% of the theoretical maximum, which is normal once protocol overhead is accounted for.
Data Transfer
Convert mbps to mb/s
1 megabit per second equals 0.125 megabytes per second. Enter a value below to convert instantly.
Megabits per second to megabytes per second is a division by eight, and it explains the most common complaint about home internet: a 100 Mbps connection downloads at about 12.5 MB/s at best. Nothing is being withheld — the two units differ by the eight bits in a byte.
1 Mbit/s
0.125 MB/s
Multiply the number of megabits per second by 0.125 to get megabytes per second. How this is calculated
Need the other direction? Convert megabyte per second to megabit per second →
Formula
Multiply the number of megabits per second by 0.125 to get megabytes per second.
Step by step
- Start with 1 Mbit/s.
- Multiply by the conversion factor 0.125.
- 1 × 0.125 = 0.125 MB/s.
Megabits per Second to Megabytes per Second conversion table
| Megabits per Second (Mbit/s) | Megabytes per Second (MB/s) |
|---|---|
| 1 | 0.125 |
| 2 | 0.25 |
| 5 | 0.625 |
| 10 | 1.25 |
| 50 | 6.25 |
| 100 | 12.5 |
| 500 | 62.5 |
| 1,000 | 125 |
Where megabits per second and megabytes per second are used together
Estimating a download time
A 4 GB file on a 100 Mbps connection needs 4,000 MB ÷ 12.5 MB/s ≈ 320 seconds at best. Real transfers take longer because of overhead, server limits and contention.
Video streaming requirements
Streaming services publish requirements in Mbps — typically 5 Mbps for HD and 15–25 Mbps for 4K. That is 0.6 MB/s and 1.9–3.1 MB/s of actual data, which is how you estimate monthly usage against a data cap.
Storage and network interfaces
A 1 Gbps Ethernet port carries at most 125 MB/s, which is slower than any modern SSD. Interface specifications mix the two conventions freely, so converting is the only way to compare them.
Everyday megabits per second worth knowing
Values people actually look up, with the reason each one comes up. Every figure is calculated with the same engine as the converter above.
| Megabit per Second (Mbit/s) | Megabyte per Second (MB/s) | What it is |
|---|---|---|
| 8 | 1 | Exactly one megabyte per second |
| 25 | 3.125 | A 4K streaming requirement |
| 50 | 6.25 | A basic broadband plan |
| 100 | 12.5 | A common broadband plan |
| 300 | 37.5 | A fast broadband plan |
| 500 | 62.5 | A fast broadband plan |
| 1,000 | 125 | A gigabit connection |
| 2,500 | 312.5 | A multi-gigabit connection |
How these two units are defined
A bit is a single binary digit; a byte is eight bits. Network and link speeds are quoted in bits per second by long-standing convention, written Mbps or Mbit/s with a lower-case b. File sizes and transfer rates are in bytes, written MB/s with an upper-case B. Both use decimal SI prefixes here, so 1 Mbps is 1,000,000 bits per second and 1 MB/s is 1,000,000 bytes per second — meaning the conversion is exactly a factor of eight, with no binary-prefix complication.
Rounding and precision
The factor of eight is exact. What is not exact is the relationship between a link speed and an observed transfer rate: TCP/IP, Ethernet framing and encryption all consume bandwidth, so real throughput typically lands at 85–95% of the theoretical figure even on an otherwise idle line. Treat the converted number as a ceiling rather than a prediction.
Mistakes people make with this conversion
-
Reading Mbps as MB/s
The case of the 'b' carries the whole meaning. 100 Mbps is 12.5 MB/s; reading it as 100 MB/s overstates the connection eightfold.
-
Expecting to hit the contracted speed exactly
Protocol overhead alone accounts for several percent. A line delivering 90% of its rated speed under load is performing normally.
-
Applying 1,024 to network units
Network and transfer units are decimal. Dividing by 1,048,576 instead of 1,000,000 introduces a 4.9% error on top of the bit/byte factor.
Read more about these units
Sources for this page
- Definitions of the SI units: The binary prefixes
- SI Brochure — The International System of Units (SI), 9th edition
Content on this page last reviewed 12 August 2026. Spotted an error? Report it — see also how these values are calculated.
Convert Megabit per Second to other data transfer units
1 Mbit/s expressed in every other data transfer unit on this site.
- Bit per Second bit/s 1,000,000
- Kilobit per Second kbit/s 1,000
- Megabit per Second Mbit/s 1
- Gigabit per Second Gbit/s 0.001
- Terabit per Second Tbit/s 0.000001
- Byte per Second B/s 125,000
- Kilobyte per Second KB/s 125
- Megabyte per Second MB/s 0.125
- Gigabyte per Second GB/s 0.000125
- Terabyte per Second TB/s 1.25e-7
- Kibibit per Second Kibit/s 976.5625
- Mebibit per Second Mibit/s 0.95367432
- Gibibit per Second Gibit/s 0.00093132257
- Kibibyte per Second KiB/s 122.07031
- Mebibyte per Second MiB/s 0.11920929
- Gibibyte per Second GiB/s 0.00011641532
- Megabyte per Minute MB/min 7.5
- Gigabyte per Hour GB/h 0.45
- Gigabyte per Day GB/d 10.8
- T1 (DS1) T1 0.64766839
- T3 (DS3) T3 0.022353362
- E1 E1 0.48828125
- E3 E3 0.029096834
- OC-1 OC-1 0.019290123
- OC-3 OC-3 0.0064300412
- OC-12 OC-12 0.0016075103
- OC-48 OC-48 0.00040187757
- OC-192 OC-192 0.00010046939
- OC-24 OC-24 0.00080375514
- OC-768 OC-768 0.000025117348
- STS-1 (payload) STS-1 payload 0.02020202
- STS-3 (payload) STS-3 payload 0.0066517667
- STS-24 (signal) STS-24 0.00080375514
- Virtual Tributary 1 (signal) VT1 0.5787037
- Virtual Tributary 2 (signal) VT2 0.43402778
- Virtual Tributary 6 (signal) VT6 0.15842839
- Virtual Tributary 6 (payload) VT6 payload 0.16666667
- T0 (payload) T0 17.857143
- T0 (B8ZS payload) T0 B8ZS 15.625
- T1 (payload) T1 payload 0.74404762
- T1C (signal) T1C 0.31725888
- T1C (payload) T1C payload 0.37202381
- T2 (signal) T2 0.15842839
- T3 (payload) T3 payload 0.026573129
- T3Z (payload) T3Z payload 0.023251488
- T4 (signal) T4 0.0036472923
- E.P.T.A. 1 (payload) EPTA1 payload 0.52083333
- E.P.T.A. 2 (signal) EPTA2 0.11837121
- E.P.T.A. 2 (payload) EPTA2 payload 0.13020833
- E.P.T.A. 3 (payload) EPTA3 payload 0.032552083
- H0 H0 2.6041667
- H11 H11 0.65104167
- H12 H12 0.52083333
- ISDN (single channel) ISDN 1B 15.625
- ISDN (dual channel) ISDN 2B 7.8125
- Ethernet (10BASE-T) Ethernet 0.1
- Ethernet (fast) Fast Ethernet 0.01
- USB 1.1 (full speed) USB 0.083333333
- FireWire (IEEE-1394) FireWire 0.0025
- Modem (110) 110 baud 9,090.9091
- Modem (300) 300 baud 3,333.3333
- Modem (1200) 1200 baud 833.33333
- Modem (2400) 2400 baud 416.66667
- Modem (9600) 9600 baud 104.16667
- Modem (14.4k) 14.4k 69.444444
- Modem (28.8k) 28.8k 34.722222
- Modem (33.6k) 33.6k 29.761905
- Modem (56k) 56k 17.857143
- SCSI (Async) SCSI async 0.083333333
- SCSI (Sync) SCSI sync 0.025
- SCSI (Fast) SCSI fast 0.0125
- SCSI (Fast Ultra) SCSI fast ultra 0.00625
- SCSI (Fast Ultra Wide) SCSI fast ultra wide 0.003125
- SCSI (Ultra-2) SCSI Ultra-2 0.0015625
- SCSI (Ultra-3) SCSI Ultra-3 0.00078125
- IDE (PIO mode 0) PIO 0 0.037878788
- IDE (PIO mode 1) PIO 1 0.024038462
- IDE (PIO mode 2) PIO 2 0.015060241
- IDE (PIO mode 3) PIO 3 0.011261261
- IDE (PIO mode 4) PIO 4 0.0075301205
- IDE (DMA mode 0) DMA 0 0.029761905
- IDE (DMA mode 1) DMA 1 0.0093984962
- IDE (DMA mode 2) DMA 2 0.0075301205
- IDE (UDMA mode 1) UDMA 1 0.005
- IDE (UDMA mode 2) UDMA 2 0.0037878788
- IDE (UDMA mode 3) UDMA 3 0.0025
- IDE (UDMA mode 4) UDMA 4 0.0018939394
About the megabit per second
The megabit per second (Mbit/s) is a Metric unit of data transfer.
About the megabyte per second
The megabyte per second (MB/s) is a Metric unit of data transfer.
Related conversions
Frequently asked questions
Why is my download speed one eighth of my plan?
Because a byte is eight bits. Connections are sold in megabits per second and downloads are reported in megabytes per second, so a 100 Mbps plan gives at most 12.5 MB/s. That is the expected result, not a fault.
How long does a 4 GB download take on 100 Mbps?
At the theoretical maximum of 12.5 MB/s, about 320 seconds — a little over five minutes. Allow 10–15% more for protocol overhead and any contention on the line.
What speed do I need for 4K streaming?
Streaming services typically ask for 15–25 Mbps for 4K, which is 1.9–3.1 MB/s of actual data. Multiple simultaneous streams add up, which is the usual reason a nominally fast connection struggles.
How many megabytes per second are in a megabit per second?
One megabit per second equals 0.125 megabytes per second.
How do you convert megabits per second to megabytes per second?
Multiply the number of megabits per second by 0.125 to get megabytes per second.
What is 1 megabyte per second in megabits per second?
One megabyte per second equals 8 megabits per second.
When would I convert megabits per second to megabytes per second?
This conversion is common when internet speeds, downloads, and networking.