Download Time Calculator
Wondering how long a movie download, software update, or game will take? Enter the file size and your download speed below to get an exact estimate in seconds, minutes, and hours. The calculator converts file size to bits and divides by your connection speed in bits per second. It also shows a speed comparison table so you can see how the same download would fare at five common internet speeds (5 Mbps, 25 Mbps, 100 Mbps, 500 Mbps, and 1 Gbps). File sizes can be entered in MB or GB. Download speeds can be entered in Mbps (the unit used by internet providers). Remember that real-world download speeds are typically 50-80% of your advertised plan speed due to network overhead and congestion.
Download time formula
Download time (seconds) = (file size in MB x 8) / speed in Mbps
Or equivalently: time = file size in bits / speed in bps
Common download time examples
| File / Content | Typical size | At 100 Mbps | At 1 Gbps |
|---|---|---|---|
| MP3 song | 5 MB | 0.4 sec | 0.04 sec |
| HD movie | 4 GB | 5.3 min | 32 sec |
| 4K movie | 50 GB | 67 min | 6.7 min |
| PC game | 60 GB | 80 min | 8 min |
| OS install | 10 GB | 13 min | 1.3 min |
Download time: frequently asked questions
How do I calculate download time?
Download time = file size in bits / speed in bits per second. First, convert the file size to bits: multiply megabytes by 8,000,000 (8 million). Then divide by your speed in Mbps * 1,000,000. For example, a 4 GB (32,000 Mbits) file at 100 Mbps takes 32,000 / 100 = 320 seconds, or about 5 minutes 20 seconds. In practice, real-world speeds are typically 50-80% of your advertised maximum.
Why is my actual download speed slower than my plan speed?
Advertised internet speeds are theoretical maximums under ideal conditions. Real-world speeds are lower due to: network congestion (especially during peak hours), Wi-Fi signal loss compared to wired ethernet, the speed limits of the server you are downloading from, router processing overhead, and TCP/IP protocol overhead (typically 5-10% of bandwidth). For large downloads, connecting via ethernet cable and downloading during off-peak hours gives the best results.
Why is download speed measured in Mbps but file size in MB?
Download speed uses bits (Mbps = megabits per second) while file size uses bytes (MB = megabytes). Network engineers historically measured speeds in bits, while storage was measured in bytes. Since 1 byte = 8 bits, a 100 Mbps connection downloads at 12.5 MB/s. This inconsistency persists because the two industries developed their conventions independently.
What is a good internet speed for downloading large files?
For most uses: 25 Mbps (3.1 MB/s) is considered 'fast' by the FCC for a single user. 100 Mbps downloads a 1 GB file in about 80 seconds. 1 Gbps downloads 1 GB in about 8 seconds. For large game downloads (50-100 GB), a 100 Mbps connection takes 1 to 2 hours. A 1 Gbps connection brings this to 7 to 15 minutes.
Does the number of files affect download speed?
Downloading many small files is typically slower than downloading one large file of the same total size. Each file requires a separate HTTP connection request, which adds latency overhead. This is why software is distributed in archives (ZIP, tar.gz) rather than loose files: a single connection is much more efficient. Parallel downloads from multiple connections or download managers can partially offset this for many-file scenarios.
Official sources
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.