Convert bits to bytes and vice versa. Translate network speeds (Mbps) to file transfer rates (MB/s) with this free online tool.
Network speeds are measured in bits per second while file sizes are measured in bytes. There are 8 bits in every byte, so a 100 Mbps internet connection delivers a maximum of 12.5 MB per second. This confusion is one of the most common frustrations in computing—people wonder why their "100 Mbps" connection can't download a 100 MB file in one second.
This converter bridges the gap between bits and bytes at any scale. Enter a value in bits (b, Kb, Mb, Gb) or bytes (B, KB, MB, GB) and instantly see the equivalent in the other system. It's especially useful for network planning, bandwidth budgeting, and understanding real-world download speeds versus advertised connection rates. The calculator also accounts for network protocol overhead that reduces effective throughput.
This measurement provides a critical foundation for capacity planning and performance budgeting, helping teams align infrastructure resources with application requirements and growth projections.
ISPs advertise in megabits per second but downloads show megabytes per second. This converter instantly translates between the two so you can accurately estimate download times, verify you're getting the bandwidth you pay for, and plan network capacity for your applications. Having accurate metrics readily available streamlines incident postmortems, architecture reviews, and technology roadmap discussions with engineering leadership and product teams.
Bytes = Bits / 8. Bits = Bytes × 8. Transfer Rate (MB/s) = Connection Speed (Mbps) / 8.
Result: 62.5 MB/s
500 Mbps divided by 8 = 62.5 MB/s maximum theoretical transfer rate. With typical TCP/IP overhead of about 5%, the real-world rate is approximately 59.4 MB/s. A 1 GB file would take roughly 16.8 seconds to download.
The core relationship is simple: 1 byte = 8 bits. But this 8x multiplier compounds confusingly across prefixes. 1 Mbps = 0.125 MBps. 1 Gbps = 125 MBps. A 10 Gbps server NIC delivers a maximum of 1.25 GB per second of actual data throughput.
Raw bit rate doesn't equal usable throughput. Ethernet frames add headers, TCP adds sequence numbers and checksums, and IP adds routing information. For a standard 1500-byte Ethernet frame, about 38 bytes are overhead, reducing usable throughput by approximately 2.5%. For small packets, overhead is proportionally much larger.
When planning bandwidth, convert everything to the same unit. If your application needs to transfer 500 GB per day, that's about 46.3 Mbps sustained throughput. Add 30% headroom for peaks and you need at least 60 Mbps of dedicated bandwidth. Always plan in bytes for storage and bits for network links.
Historically, telecommunications measured data rates in bits because serial communication sends one bit at a time. ISPs continued this convention, and the larger numbers in bits (e.g., 100 Mbps vs 12.5 MBps) also look better in marketing.
There are exactly 8 bits in 1 byte. This has been the standard since the 1960s. Some historical systems used 6, 7, or 9 bits per byte, but modern computing universally uses 8.
Several factors reduce real-world speed: protocol overhead (TCP/IP headers consume 3-5%), network congestion, server-side limitations, Wi-Fi interference, and distance from the router. "Up to" speeds mean maximum under ideal conditions.
Mbps (lowercase b) means megabits per second—used for network speeds. MBps (uppercase B) means megabytes per second—used for file transfer rates. 1 MBps = 8 Mbps. Be careful: some speed tests show results in both.
Convert your speed to bytes per second (divide Mbps by 8 for MBps), then divide the file size by the transfer rate. For a 4 GB file on a 100 Mbps connection: 4,000 MB / 12.5 MBps = 320 seconds = about 5.3 minutes.
Technically yes—kilobits use 1000 bits and kibibits use 1024 bits—but in networking, kilobits almost always means 1000 bits. The IEC binary prefixes are rarely used for network speeds, only for storage.