Decimal or binary: two ways to count bytes
Byte units have two meanings. Decimal (SI) steps by 1,000, which is how drive makers, macOS, iOS, Android and network gear count. Binary steps by 1,024, which is how Windows and RAM count; the IEC gives these sizes their own names (KiB, MiB, GiB) so they cannot be confused. Bits are always decimal: 1 Kb = 1,000 b, and 1 B = 8 b. The converter above has a switch for the mode.
| Unit | Decimal (SI) | Binary |
|---|---|---|
| KB/s kilobyte per second | 1,000 B/s | 1,024 B/s |
| MB/s megabyte per second | 1,000,000 B/s | 1,048,576 B/s |
| GB/s gigabyte per second | 1,000,000,000 B/s | 1,073,741,824 B/s |
Popular bandwidth conversions
Data transfer rate units
Network speeds are sold in bits per second, which are always decimal (1 Mbps = 1,000 kbps). Download dialogs show bytes per second, which some apps count in decimal (1 MB/s = 1,000 KB/s) and others in binary (1 MB/s = 1,024 KB/s). Because a byte is 8 bits, a 100 Mbps connection tops out around 12.5 MB/s (11.9 binary MB/s) before protocol overhead.
| Unit | Symbol | In bits per second | Definition |
|---|---|---|---|
| Bit per second | bps | 1 bps | |
| Kilobit per second | kbps | 1,000 bps | |
| Megabit per second | Mbps | 1,000,000 bps | One million bits per second, the usual unit for broadband and Wi-Fi speeds. |
| Gigabit per second | Gbps | 1,000,000,000 bps | |
| Terabit per second | Tbps | 1,000,000,000,000 bps | |
| Byte per second | B/s | 8 bps | |
| Kilobyte per second | KB/s | 8,000 bps | |
| Megabyte per second | MB/s | 8,000,000 bps | One million bytes per second, how browsers and download managers show speed. |
| Gigabyte per second | GB/s | 8,000,000,000 bps | |
| Mebibyte per second | MiB/s | 8,388,608 bps |
Calculate with bandwidth
The smart calculator does arithmetic across bandwidth units and picks a sensible unit for the answer. Try 500 MB / 20 s to Mbps.
Questions and answers
Which bandwidth units can I convert?
All 10: bits per second, kilobits per second, megabits per second, gigabits per second, terabits per second, bytes per second, kilobytes per second, megabytes per second, gigabytes per second, mebibytes per second.
What is the SI unit of bandwidth?
This converter uses the bit per second (bps) as its base unit. Network speeds are sold in bits per second, which are always decimal (1 Mbps = 1,000 kbps). Download dialogs show bytes per second, which some apps count in decimal (1 MB/s = 1,000 KB/s) and others in binary (1 MB/s = 1,024 KB/s). Because a byte is 8 bits, a 100 Mbps connection tops out around 12.5 MB/s (11.9 binary MB/s) before protocol overhead.
Why is my download speed lower than my internet plan?
Plans are sold in megabits per second (Mbps) and downloads show megabytes per second (MB/s). A byte is 8 bits, so 100 Mbps is at most 12.5 MB/s, or 11.92 MB/s if your download manager counts in binary, and protocol overhead takes a little more.
Is 1 MB/s 1,000 KB/s or 1,024 KB/s?
It depends on the app. Decimal counting gives 1 MB/s = 1,000 KB/s; binary counting (common in Windows tools and some download managers) gives 1,024 KB/s. Use the Decimal / Binary switch to match your app. Bit rates like Mbps are always decimal.
How precise are the results?
Factors are the exact legal definitions where one exists (an inch is exactly 2.54 cm, a pound exactly 0.45359237 kg). Results show 10 significant digits by default; the precision menu offers 4 to 15.
Does the bandwidth converter work offline?
Yes. ConvertEasy is a progressive web app: after your first visit it keeps working with no connection, and you can install it to your home screen from the browser menu.