Data Transfer Speed Converter, Mbps, Gbps & MB/s Free
This data transfer speed converter switches instantly between bps, Kbps, Mbps, Gbps, and their byte based equivalents like MB/s and GB/s. See every unit at once and estimate download times for real file sizes, no sign up needed.
Why your 100 Mbps plan downloads at 12.5MB/s, and how this converter tracks bits versus bytes
Network speed and file size are measured in different units by long standing convention, and mixing them up is the single most common cause of the complaint that your internet feels slower than advertised. ISPs, routers and Ethernet standards report speed in bits per second. Operating systems and download managers report file transfer progress in bytes per second. A byte is 8 bits, so a 100 Mbps connection tops out around 12.5 MB/s, not 100 MB/s. This tool keeps that distinction explicit in its unit list rather than letting you guess.
The calculation is pure client side arithmetic against a static factor table. Nothing you type is transmitted anywhere, which is a little ironic for a bandwidth calculator, but accurate.
How the conversion and time estimate work
Full unit table, factor relative to one bit per second
| Unit | Kind | Factor (bps) |
|---|---|---|
| bps | Bit rate | 1 (base unit) |
| Kbps | Bit rate | 1,000 |
| Mbps | Bit rate | 1,000,000 |
| Gbps | Bit rate | 1,000,000,000 |
| Tbps | Bit rate | 1,000,000,000,000 |
| B/s | Byte rate | 8 |
| KB/s | Byte rate | 8,000 |
| MB/s | Byte rate | 8,000,000 |
| GB/s | Byte rate | 8,000,000,000 |
| TB/s | Byte rate | 8,000,000,000,000 |
The two supporting calculators bundled in
Transfer time estimate
Enter a file size in MB, GB or TB alongside your speed and the tool converts the file to bits, divides by your bits per second rate, and prints a plain language duration, from milliseconds up to days.
Reference speed table
A clickable list of common connection types from dial-up at 56 Kbps through Wi-Fi 6 at roughly 1.2 Gbps and 10 Gigabit Ethernet loads that speed straight into the converter, useful when you know the standard but not the exact number.
Where the units come from
Bit based rates trace back to telecommunications and modem era engineering, where signal rate was the natural quantity to measure on a wire. USB and Ethernet standards inherited that convention: USB 2.0 is rated at 480 Mbps, USB 3.0 at 5 Gbps, and Gigabit Ethernet is defined in the IEEE 802.3ab standard as exactly 1,000,000,000 bits per second. Wi-Fi generational names like Wi-Fi 5 and Wi-Fi 6 are marketing labels from the Wi-Fi Alliance layered on top of the underlying 802.11ac and 802.11ax technical standards, with real world throughput typically well below the headline number due to overhead and interference.
Bandwidth references
- IEEE 802.3 Ethernet Working Group defines the bit rate standards behind Gigabit and 10 Gigabit Ethernet figures used in the reference table.
- USB Implementers Forum publishes the official signaling rates for USB 2.0 and USB 3.0 cited in this tool.
- Wi-Fi Alliance maintains the Wi-Fi generational naming and the underlying 802.11 throughput specifications.
- BIPM SI Brochure is the source for the decimal kilo, mega, giga and tera prefixes used throughout the bit rate table.
Reading a speed claim correctly
Checking whether an advertised broadband plan will actually download a game or movie in the time you expect, converting a router’s reported link speed in Mbps into the MB/s figure your download manager displays, estimating backup or migration windows for large datasets moving across a network, comparing USB and Wi-Fi generations when choosing hardware, and translating a hosting provider’s bandwidth cap from Gbps into a monthly data transfer budget you can actually plan around.
FAQ: Data Transfer Speed Converter
This is the single most common confusion in networking, and it’s simply a unit mismatch, not a problem with your connection. ISPs advertise speed in megabits per second (Mbps), but your operating system and download managers show progress in megabytes per second (MB/s), and one byte equals 8 bits. A “100 Mbps” plan has a theoretical maximum of 100 ÷ 8 = 12.5 MB/s, which is exactly what this converter shows when you switch units.
Advertised speeds represent the theoretical maximum under ideal conditions. Real world throughput is reduced by network overhead (protocol headers), Wi-Fi signal strength and interference, how many devices share the connection simultaneously, the server’s own upload speed on the other end, and general network congestion. Getting 70 to 90% of your advertised speed in a real download is generally considered normal and healthy.
1000, the decimal convention, which matches how internet service providers, networking hardware, and speed test tools universally report data transfer speeds. This is different from file storage sizes on your computer, which traditionally use 1024 based binary units, that distinction is covered specifically by a dedicated data storage converter rather than this speed focused tool.
It’s a theoretical maximum calculation, actual download time will typically be somewhat longer due to the same real world factors that reduce throughput below advertised speeds, overhead, congestion, server limitations, and shared bandwidth. Use it as a useful lower bound estimate rather than an exact prediction.
For general browsing and streaming HD video, 25 to 100 Mbps comfortably covers most households. For 4K streaming, gaming, or multiple simultaneous heavy users, 100 to 300 Mbps is a more comfortable range. Fiber connections increasingly offer 500 Mbps to several Gbps for power users, large file transfers, or households with many connected devices.
Data center and server network interfaces (1 Gbps, 10 Gbps, 25 Gbps, and beyond) are standardized around bits per second, consistent with general networking convention, and describe the raw capacity of the physical network port itself rather than any specific file transfer, which is why server specs are almost always listed as bit based Gbps rather than byte based GB/s.
Yes, the same unit conversion math applies identically to upload speeds, this converter works the same way whether you’re calculating an upload or a download, the underlying bits to bytes relationship doesn’t change based on direction.
No, all calculations happen locally in your browser, nothing is sent to a server or stored.
From the blog
Reading around units
Where measurement systems came from and why two of them still argue.
