Mbps vs MB/s: the difference
Internet providers advertise speed in megabits per second (Mbps, lowercase b). Browsers, game launchers and download managers show megabytes per second (MB/s, uppercase B). One byte is eight bits, so the same speed looks eight times smaller in MB/s.
MB/s = Mbps ÷ 8 · Mbps = MB/s × 8
Worked example: a 300 Mbps plan downloads at up to 300 ÷ 8 = 37.5 MB/s. If Steam shows a download at 35 MB/s, you're getting about 93% of your plan, which is excellent.
Conversion table
| Plan speed | MB/s | 1 GB downloads in |
|---|---|---|
| 10 Mbps | 1.25 MB/s | 13 min 20 s |
| 25 Mbps | 3.1 MB/s | 5 min 20 s |
| 50 Mbps | 6.25 MB/s | 2 min 40 s |
| 100 Mbps | 12.5 MB/s | 80 s |
| 300 Mbps | 37.5 MB/s | 27 s |
| 500 Mbps | 62.5 MB/s | 16 s |
| 1 Gbps | 125 MB/s | 8 s |
Times in this table are at the full line speed; in practice allow about 10% more. Our download time calculator does this for any file size.
Decimal and binary units
Network speeds always use decimal prefixes: 1 Mbps is exactly 1,000,000 bits per second and 1 Gbps is 1,000 Mbps. File sizes are less consistent. Storage makers and most apps use decimal (1 GB = 1,000,000,000 bytes), but Windows and some tools use binary units (1 GiB = 1,073,741,824 bytes) and still label them "GB" or "MB". This converter uses decimal units throughout, which match how speeds are sold and measured.
Kbps and Gbps
- Kbps (kilobits per second) is used for slow links and audio: a music stream needs about 160–320 Kbps.
- Gbps (gigabits per second) is used for fiber and local networks: 1 Gbps = 1,000 Mbps = 125 MB/s.
Frequently asked questions
How many MB/s is 100 Mbps?
100 Mbps is 12.5 MB/s, because there are 8 bits in a byte (100 ÷ 8 = 12.5). In practice downloads reach about 11–12 MB/s on a 100 Mbps line because of network overhead.
Is Mbps the same as MB/s?
No. Mbps is megabits per second and MB/s is megabytes per second. One megabyte is eight megabits, so 8 Mbps equals 1 MB/s.
How many Mbps is 1 Gbps?
1 Gbps is 1,000 Mbps, which is 125 MB/s. Gigabit plans often measure 900–940 Mbps in a speed test because of overhead and equipment limits.
Why do internet providers use Mbps?
Networking has always measured speed in bits per second, because data travels over the wire one bit at a time. It also makes the numbers bigger, which helps marketing.
Conversions use decimal (SI) units: 1 kilobit = 1,000 bits, 1 megabyte = 1,000,000 bytes.