Bandwidth Converter · Download Time
Data Rate & Download Time Calculator
Eliminate confusion between ISP advertised Mbps and actual download MB/s. Convert network speeds and estimate file download duration.
Mathematical Formula · 100% Client-Side · Zero Server Transmission
Speed Value
Speed Converter
💡 Popular Broadband Presets
💡 Fundamental Rule: 1 Byte = 8 bits. An ISP's advertised 100 Mbps connection gives a maximum theoretical download speed of 100 ÷ 8 = 12.5 MB/s.
Conversion Result
100 Mbps ➜ MB/s
12.5MB/s
📊 Equivalent Data Rates
| Unit | Rate |
|---|---|
| bps | 100,000,000 |
| Kbps | 100,000 |
| Mbps | 100 |
| Gbps | 0.1 |
| KB/s | 12,500 |
| MB/s | 12.5 |
| GB/s | 0.0125 |
| KiB/s | 12,207.03 |
| MiB/s | 11.921 |
| GiB/s | 0.01164 |
Conversion desk
Why does a 100 Mbps connection only download at ~12.5 MB/s?
Internet Service Providers (ISPs) advertise bandwidth in Megabits per second (Mbps, lowercase 'b'), while browsers and download managers measure file sizes in Megabytes per second (MB/s, uppercase 'B').
Because 1 Byte equals 8 bits, divide your advertised Mbps by 8 to find the theoretical maximum download speed (100 Mbps ÷ 8 = 12.5 MB/s). Factoring in 5-10% TCP/IP protocol overhead and wireless attenuation yields roughly 11.5 MB/s in practice.
Download Speed (MB/s) = ISP Speed (Mbps) ÷ 8; Time = File Size ÷ (Speed × Efficiency)
FAQ
Data Rate & Download Time Calculator · FAQ
What is the difference between Mbps and MB/s?
Mbps is Megabits per second, used by network providers. MB/s is Megabytes per second, used for file storage and downloads. 1 MB/s = 8 Mbps.
Why doesn't my Gigabit internet reach 125 MB/s?
Reaching theoretical Gigabit speeds requires end-to-end Gigabit hardware: Cat5e/6 cables, gigabit Ethernet router/ports, and an unthrottled remote server.
How long does a 50 GB game take to download?
On a 100 Mbps connection, 50 GB takes roughly 1h 14m. On 300 Mbps fibre it takes ~24m, and on a 1 Gbps connection it finishes in about 7m.