Enter your file size and transfer speed to find out exactly how long your data transfer will take. Choose your file size unit (MB, GB, TB) and speed unit (Mbps, Gbps, MB/s) to match your connection type — the calculator returns transfer time broken down into hours, minutes, and seconds, plus the equivalent speed in multiple units.
Transfer Time
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Total Seconds
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Total Minutes
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Speed in Mbps
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Speed in MB/s
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Transfer time is calculated using the formula: Duration = File Size / Transfer Speed. Make sure both values use compatible units — convert file size to bits and divide by the speed in bits per second. For example, a 500 MB file at 15 Mbps takes (500 × 8) / 15 ≈ 266.67 seconds.
Mbps stands for megabits per second, while MB/s stands for megabytes per second. Since 1 byte = 8 bits, 1 MB/s is equal to 8 Mbps. Internet speeds are typically advertised in Mbps, while file transfer and storage speeds are often quoted in MB/s.
Windows 11 ISO is approximately 5.2 GB. At a typical broadband speed of 100 Mbps, it would take roughly (5.2 × 8 × 1024) / 100 ≈ 425 seconds, or about 7 minutes. Slower connections of 25 Mbps would take around 28 minutes.
USB 3.0 (also called USB 3.1 Gen 1) has a theoretical maximum transfer rate of 5 Gbps (gigabits per second), which equals about 625 MB/s. In practice, real-world speeds are typically 300–400 MB/s due to overhead and device limitations.
Data transfer speed is calculated by dividing the amount of data transferred by the time it took: Speed = File Size / Duration. For example, if you transferred 1 GB in 80 seconds, your speed is (1 × 8 × 1024) / 80 = 102.4 Mbps.
Advertised speeds represent theoretical maximums under ideal conditions. Real-world speeds are reduced by network congestion, protocol overhead, hardware limitations, Wi-Fi interference, and server-side throttling. A common rule of thumb is to expect 50–80% of the advertised speed in practice.
At USB 3.0 speeds (400 MB/s real-world), 1 TB takes about 2,621 seconds or roughly 44 minutes. Over a 100 Mbps internet connection, it would take approximately 22.8 hours. Use this calculator to get an exact estimate for your specific speed.
Yes. Enter your total backup size as the file size and your internet upload speed as the transfer speed. ISPs typically provide asymmetric connections where upload speed is much slower than download speed, so make sure to use your upload speed for backup calculations.