Mbps to bytes per second
To convert Mbps to bytes per second, multiply by 1,000,000 and divide by 8, which is the same as multiplying by 125,000. A 300 Mbps plan can deliver at most 37,500,000 B/s.
Tip: paste a reading like “12.4 MB/s” and the unit is picked for you.
1 Mbps equals:
- bps1,000,000
- kbps1,000
- Mbps1
- Gbps0.001
- B/s125,000
- kB/s125
- MB/s0.125
- GB/s0.000125
- MiB/s0.119209
Runs entirely in your browser. Nothing you type is sent anywhere.
Formula
1 Mbps = 1,000,000 bits and 1 B/s = 8 bits, so:
Common conversions
| Mbps | B/s |
|---|---|
| 10 Mbps | 1,250,000 B/s |
| 25 Mbps | 3,125,000 B/s |
| 50 Mbps | 6,250,000 B/s |
| 100 Mbps | 12,500,000 B/s |
| 200 Mbps | 25,000,000 B/s |
| 300 Mbps | 37,500,000 B/s |
| 500 Mbps | 62,500,000 B/s |
| 1,000 Mbps | 125,000,000 B/s |
| 2,000 Mbps | 250,000,000 B/s |
Examples: when you need the answer in bytes
Speeds are marketed in bits, but software that stores, buffers or throttles data almost always works in bytes. Converting first avoids an 8× mistake in a config file.
- Setting a bandwidth cap. You want a backup job to use no more than 20 Mbps of a shared line. Many sync and download tools take a limit in bytes per second: 20 × 125,000 = 2,500,000 B/s. Check whether the tool counts a kilobyte as 1,000 or 1,024 bytes before typing 2,500 k.
- Sizing a buffer. A 50 Mbps video stream delivers 6,250,000 bytes each second, so a buffer holding five seconds needs about 31,250,000 bytes.
- Estimating a plan's daily ceiling. At a sustained 100 Mbps a connection moves 12,500,000 B/s; over 86,400 seconds that is 1,080,000,000,000 bytes, or 1.08 TB a day. The data transfer calculator does this for any duration.
Pitfall: expecting the full figure in practice
The converted number is a ceiling. TCP/IP headers, Wi-Fi and the remote server all take a share, so an application usually sees less than the plan speed ÷ 8. On a wired gigabit link, speed tests commonly top out near 940 Mbps, which is 117,500,000 B/s rather than 125,000,000. If you are planning how long a file will take, the download time calculator has an efficiency option for this.
If your answer needs to be in MB/s instead of plain bytes, use Mbps to MB/s, which divides by 8 directly. For the other direction, from a byte count back to Mbps, use bytes to Mbps. The difference between the two units is explained in bits vs bytes.
Frequently asked questions
How many bytes per second is 100 Mbps?
100 Mbps is 12,500,000 bytes per second, or 12.5 MB/s: 100,000,000 bits ÷ 8.
What number do I enter for a 20 Mbps limit in a tool that takes bytes per second?
Enter 2,500,000 B/s. If the tool asks for kilobytes per second, that is 2,500 kB/s in decimal units or about 2,441 KiB/s if it counts 1,024 bytes per kilobyte.
Why is my measured byte rate lower than the plan speed divided by 8?
Protocol headers, retransmissions, Wi-Fi and server limits all use part of the capacity. On wired gigabit, about 940 Mbps (117.5 MB/s) is a typical best case.