Bandwidth & Transfer Speed Calculator
Estimate how long a file transfer could take, or work out the connection speed needed to finish within your target time.
Transfer details
Choose a mode, enter the file size, and adjust the connection speed or target transfer time.
Estimated transfer time
Estimated time using the selected connection speed and efficiency.
Transfer summary
Important distinction
Internet speed is normally advertised in bits per second (Mbps), while file sizes are commonly shown in bytes (MB). One byte contains eight bits.
This is an estimate. Actual speed can vary with Wi-Fi signal, network congestion, server limits, and other conditions.
How transfer time is estimated
File bits = File size in bytes × 8
Effective speed = Connection speed × Efficiency
Transfer time = File bits ÷ Effective speed
Required speed = File bits ÷ Target time ÷ Efficiency
The calculator uses decimal units: 1 MB = 1,000,000 bytes and 1 Mbps = 1,000,000 bits per second. Some operating systems use binary units such as MiB and GiB, so displayed estimates may differ slightly from a device's file-size display.