Free data transfer rate converter. Convert megabits per second (Mbps) to megabytes per second (MB/s), Gbps, Kbps, and back — and instantly see real download times. Settle the bits-vs-bytes confusion once and for all.
Mbps • MB/s • Gbps • Kbps
Internet speeds are in bits, file sizes in bytes. We handle the ÷8 automatically so you stop second-guessing.
See exactly how long a 1 GB file, 5 GB movie, or 50 GB game takes at your connection's speed.
All conversions run in your browser — no server, no account, nothing sent anywhere.
The single biggest source of confusion in internet speeds is the difference between bits and bytes. Internet service providers advertise plans in megabits per second (Mbps), while operating systems, browsers, and download managers report transfer speed in megabytes per second (MB/s). Because 1 byte = 8 bits, your actual download speed in MB/s is roughly one-eighth of your plan's Mbps number. A 100 Mbps plan downloads at about 12.5 MB/s — not 100 MB/s.
The conversion that matters most: divide Mbps by 8 to get MB/s. 100 Mbps ÷ 8 = 12.5 MB/s. 1 Gbps (1,000 Mbps) ÷ 8 = 125 MB/s. 25 Mbps ÷ 8 = 3.125 MB/s. Going the other way, multiply MB/s by 8: a 10 MB/s download is running at 80 Mbps. Data-transfer rates use the decimal (SI) standard where "kilo" = 1,000, "mega" = 1,000,000, so 1 Mbps = 1,000 Kbps = 1,000,000 bps.
Estimating download time: divide the file size (in the same byte units) by your speed in MB/s. A 5 GB movie (5,000 MB) at 12.5 MB/s takes 5,000 ÷ 12.5 = 400 seconds ≈ 6.7 minutes. The same movie on a 1 Gbps connection (125 MB/s) takes just 40 seconds. Real-world speeds are usually 10–20% lower than the theoretical maximum due to overhead, Wi-Fi loss, and server limits.
DSL: 10–25 Mbps (1.25–3.1 MB/s). Cable: 100–500 Mbps (12.5–62.5 MB/s). Fiber: 1 Gbps (125 MB/s). 5G home: 100–600 Mbps. Streaming 4K needs ~25 Mbps.
SD video: 3 Mbps. HD (1080p): 5–8 Mbps. 4K UHD: 25 Mbps. Video call: 1.5–3 Mbps. Online gaming: 3–6 Mbps (latency matters more than raw speed).
(12.5 MB/s) — 1 GB ≈ 80 s. 5 GB movie ≈ 6.7 min. 50 GB game ≈ 67 min. 25 MB album ≈ 2 s. On 1 Gbps: 50 GB game ≈ 6.7 min.
1 byte = 8 bits. 1 Kbps = 1,000 bps. 1 Mbps = 1,000 Kbps. 1 Gbps = 1,000 Mbps. MB/s uses bytes (capital B); Mbps uses bits (lowercase b). The case of that one letter changes the value 8×.
The single most consequential fact about transfer rates is that network speeds are quoted in bits per second while file sizes are quoted in bytes — a factor of eight that makes a 100 Mbps connection deliver 12.5 MB/s, not 100. Internet providers advertise in megabits precisely because the number is larger. Real throughput is lower again: protocol overhead from TCP/IP headers, acknowledgements and retransmission typically costs 5–15%, so a connection rarely delivers its nominal rate even under ideal conditions.
MB/s = Mbps ÷ 8Transfer time (s) = file size (MB) × 8 ÷ speed (Mbps)Effective throughput ≈ nominal × 0.85 to 0.95Note the case: Mb is megabits, MB is megabyteswhere:
Assumptions: Advertised speeds are usually a maximum rather than a guarantee. Wi-Fi, disk speed at either end, and server capacity frequently bind before the connection does.
Convert a file size and connection speed into a realistic time, then compare with faster service.
Result25 GB on 100 Mbps takes about 37 minutes, not 33
The eight-fold bit/byte confusion is why a "100 Mbps" connection appears to download at only 12 MB/s and users assume they are being short-changed. They are not — the units differ. Genuine shortfalls show up as throughput well below 85% of nominal.