Bandwidth Converter (Mbps to MB/s) + Download Time
Convert internet speeds between Mbps and MB/s, plus calculate how long a file takes to download at any speed.
What this calculates
ISPs sell bandwidth in megabits per second (Mbps). Operating systems and browsers show download speed in megabytes per second (MB/s). The conversion is simply ÷8, but it trips most people up. This calculator handles both directions and adds a download-time estimator for any file size.
Formula & how it works
1 byte = 8 bits. MB/s = Mbps ÷ 8. So a '100 Mbps' connection = 12.5 MB/s peak (real-world usually 80-95 % of theoretical). Download time (seconds) = file_size_bytes ÷ (speed_in_bytes_per_second). Higher units: Gbps = 1000 Mbps; convert similarly.
Worked example
100 Mbps fiber = 12.5 MB/s. A 1 GB game update at 100 Mbps takes 1,000,000,000 bytes / 12,500,000 bytes per second ≈ 80 seconds. Real-world might be 90-120 seconds due to TCP overhead, server limits, and burst variability. 4K Netflix needs ~25 Mbps minimum.
Frequently asked questions
Why is my actual speed lower than advertised?
WiFi loss, ISP throttling, server-side limits, peak-time congestion, distance from CDN edge. Speedtest sites measure to nearby servers — they're optimistic vs typical websites/streaming.
Mbps vs MBps?
Lowercase b = bit. Capital B = byte. So Mbps (megabits/sec) is 8× smaller than MBps (megabytes/sec). News articles and ads often mix these up. Always check capitalization.
Streaming needs?
1080p Netflix: 5 Mbps. 4K Netflix: 25 Mbps. 4K HDR (Apple TV+): 40 Mbps. Twitch streaming at 1080p60: 6-8 Mbps upload. Online gaming: 3-10 Mbps with low latency more important than throughput.
Gigabit fiber worth it?
For households with multiple 4K streams, work-from-home video calls, and cloud uploads, yes. For one or two people doing normal browsing + streaming, 200-300 Mbps is plenty. Most US plans deliver under what they advertise on busy nights.