Calculate data transfer time, required connection speed, and convert between all data units — with speed presets, file presets, and a live comparison table.
Enter your file size and connection speed to calculate how long the transfer will take.
TechOreo's Bandwidth Calculator covers four modes to answer every data transfer question:
Network speeds are measured in bits per second (bps). File sizes are measured in bytes. Since 1 byte = 8 bits, a "100 Mbps" connection transfers 100 million bits — or 12.5 megabytes — per second. Always divide Mbps by 8 to find your effective MB/s download speed.
SI (decimal): KB = 1,000 bytes, MB = 1,000,000 bytes, GB = 1,000,000,000 bytes. Used by ISPs and storage manufacturers. Binary (IEC): KiB = 1,024 bytes, MiB = 1,048,576 bytes, GiB = 1,073,741,824 bytes. Used by operating systems. A "1 TB" hard drive appears as ~931 GiB in Windows due to this difference.
Raw bandwidth is never fully available for data. TCP/IP headers, acknowledgements, error correction, TLS encryption, and network congestion all consume capacity. Typical overhead is 3–5% for local LAN transfers and 10–15% for VPN-encrypted connections. This calculator lets you set overhead from 0–50% for accurate estimates.
Advertised speeds are theoretical maximums. Real-world throughput is typically 60–80% of the plan speed due to Wi-Fi attenuation, network congestion, and server limitations. Wi-Fi 6: 300–600 Mbps practical. 4G LTE: 10–50 Mbps typical. 5G: 100–900 Mbps typical. USB 3.0: ~400 MB/s. NVMe SSD: 3,500–7,000 MB/s.