How is file transfer time calculated from bandwidth?

File transfer duration in seconds equals (File Size in Bytes × 8) / (Speed in bps) × 1.05, allowing ~5% overhead for TCP/IP packet framing and handshakes.

How long does it take to download 50 GB over a 100 Mbps connection?

50 GB over 100 Mbps takes approximately 1 hour, 11 minutes, and 34 seconds with standard TCP protocol overhead.

Data Transfer Time & Bandwidth Calculator

Determine exactly how long it takes to transfer backups, virtual machine images, and datasets across any network interface.

Common Scenarios & Presets:

Total Data Size

Network Connection Speed

TCP/IP Protocol Overhead Allowance

Estimated Transfer Time

14 min, 20 sec

Calculated with 5% TCP packet framing & acknowledgement overhead.

Seconds

840.00 s

Minutes

14.00 min

Hours

0.23 hrs

Days

0.01 days

Megabits (Mb) vs. Megabytes (MB): Why Transfer Speeds Confuse Users

Internet Service Providers (ISPs) advertise connection speeds in bits per second (such as 100 Mbps or 1 Gbps), whereas files, virtual disks, and database sizes are measured in bytes (MB, GB, TB).

Because there are 8 bits in 1 byte, a 100 Mbps broadband connection has a maximum theoretical throughput of:

100 Mbps ÷ 8 = 12.5 MB/s (Megabytes per second)

TCP/IP Protocol Overhead Factor

Data transmission across Ethernet or the Internet is packetized into IP datagrams (typically with an MTU of 1500 bytes). Each packet contains Ethernet headers (14 bytes), IPv4 headers (20 bytes), and TCP headers (20 bytes), plus bidirectional TCP ACK handshake packets. In practice, protocol headers and window congestion algorithms consume roughly 3% to 7% of total available bandwidth.