How long does a download take?
Estimate download time from file size and internet speed while accounting for bits, bytes, and real-world slowdowns.
The download-time formula
File sizes are commonly shown in bytes, while internet speeds are shown in bits per second. Convert to matching units before dividing. For a simple decimal estimate, one gigabyte equals about 8,000 megabits.
Step-by-step example
For a 5 GB file, multiply 5 by 8,000 to get roughly 40,000 megabits. At 200 Mbps, divide 40,000 by 200. The theoretical result is 200 seconds, or 3 minutes 20 seconds.
A real download usually takes longer, so treat the formula as a best-case estimate rather than a promise.
Why actual download time is longer
Adding 10% to 25% to the theoretical time provides a more realistic planning range for a healthy connection. A weak or crowded network can take much longer.
- Wi-Fi signal strength and interference
- Other people or devices using the connection
- The download server’s own speed limit
- Network overhead and temporary congestion
- Slow storage or device processing
Quick estimates for a 1 GB file
Large game or video downloads scale the same way. A 50 GB download takes about 50 times as long as a 1 GB download at the same steady speed.
- 25 Mbps: about 5 minutes 20 seconds theoretically
- 50 Mbps: about 2 minutes 40 seconds
- 100 Mbps: about 1 minute 20 seconds
- 300 Mbps: about 27 seconds
- 1 Gbps: about 8 seconds
Frequently asked questions
How long does 10 GB take at 100 Mbps?
The theoretical time is about 800 seconds, or 13 minutes 20 seconds. Real conditions may add several minutes.
Does faster internet always make downloads faster?
Only until another limit—such as the server, Wi-Fi, router, or device—becomes the bottleneck.
Why does the time remaining keep changing?
The app recalculates from the recent transfer rate, which can rise and fall during a download.
Published August 3, 2026 · Reviewed for clarity and source accuracy.