Download Time Calculator
By Santaji GadepatilinUpdated October 27, 2026
Download time depends on file size and connection speed — and on remembering that speeds are in bits while files are in bytes.
How to use the download time calculator
Enter the file size, your connection speed in Mbps, and a real-world efficiency. The transfer time and effective speed are calculated.
Download time formula
time = size (bits) ÷ (speed × efficiency)
Example
A 5 GB file on a 100 Mbps connection at 90%: 40,000 Mb ÷ 90 Mbps = 444 s ≈ 7.4 minutes (11.25 MB/s).
Download times at different speeds
| File size | 25 Mbps | 100 Mbps | 300 Mbps | 1 Gbps |
|---|---|---|---|---|
| 100 MB app | 36 s | 9 s | 3 s | 1 s |
| 1 GB | 5 min 55 s | 1 min 28 s | 30 s | 9 s |
| 5 GB game update | 29 min 37 s | 7 min 24 s | 2 min 28 s | 44 s |
| 25 GB 4K movie | 148 min 8 s | 37 min 2 s | 12 min 20 s | 3 min 42 s |
| 100 GB game | 592 min 35 s | 148 min 8 s | 49 min 22 s | 14 min 48 s |
Times assume 90% real-world efficiency.
Why real downloads are slower
- Server speed: the other end may limit your download.
- Wi-Fi: walls and distance reduce speed; a wired connection is faster.
- Network congestion: evening peak times are slower.
- Protocol overhead: TCP/IP headers use a few percent of bandwidth.
Upload time
Many connections have much slower upload speeds. A 100/20 Mbps plan uploads a 5 GB video in about 37 minutes at 90% efficiency, versus about 7.4 minutes to download it.
Frequently asked questions
What is the difference between Mbps and MB/s?
Mbps is megabits per second; MB/s is megabytes per second. There are 8 bits in a byte, so 100 Mbps ≈ 12.5 MB/s.
Why is my download slower than my plan?
Network overheads, Wi-Fi, server speed and other users all reduce real throughput. 80–90% of the plan is typical on a good wired connection.
How long does a 50 GB game take on 100 Mbps?
About 74 minutes at 90% efficiency.
How long does it take to download 1 GB at 100 Mbps?
About 80 seconds at full speed, or about 90 seconds in practice.
What is the difference between Mbps and MB/s?
Mbps is megabits per second; MB/s is megabytes per second. Divide Mbps by 8 to get MB/s.