Download Time Calculator

Enter a file size and your internet speed to find out how long the download will take.

Calculate download time

--

Common file sizes

Click a row to fill the calculator with that file size.

File TypeTypical SizeAt 25 MbpsAt 100 MbpsAt 500 Mbps
Song (MP3)4 MB
HD Photo5 MB
Mobile App100 MB
OS Update6 GB
HD Movie4 GB
4K Movie25 GB
Standard Game50 GB
Large Game120 GB

How download speed translates to real time

Internet speeds are measured in megabits per second (Mbps), but file sizes are measured in megabytes (MB) or gigabytes (GB). There are 8 bits in a byte, so you need to divide your Mbps speed by 8 to get the megabytes-per-second transfer rate.

For example: if your internet speed is 100 Mbps, your actual transfer rate is 100 divided by 8, which equals 12.5 MB per second. To download a 4 GB movie, divide 4,096 MB by 12.5 MB/s to get about 328 seconds, or just under 5 and a half minutes.

This calculation assumes perfect conditions. Real download speeds are often 10-20% lower due to protocol overhead, which eats into your raw Mbps figure. The calculator above applies this automatically.

How connection speed affects a 4 GB file

Connection SpeedTransfer Rate4 GB Download Time
10 Mbps1.25 MB/s54 min 37 sec
25 Mbps3.1 MB/s21 min 50 sec
100 Mbps12.5 MB/s5 min 28 sec
500 Mbps62.5 MB/s1 min 5 sec
1 Gbps125 MB/s33 sec

Why your actual download may take longer

The calculator gives an estimate based on your stated speed. Several real-world factors can increase the actual time:

Wi-Fi vs Ethernet. Wi-Fi adds overhead and is subject to interference. A 100 Mbps plan over Wi-Fi may deliver only 40-70 Mbps in practice. Wired connections come much closer to plan speeds.
Protocol overhead. TCP/IP and HTTP protocols include header data and acknowledgment packets that reduce the portion of your connection used for actual file data by roughly 5-15%.
Server-side speed limits. The server you are downloading from may limit speeds or become overloaded. A server capped at 50 Mbps will not let you use your full 500 Mbps connection, no matter how fast it is.
Network congestion. During peak evening hours, your ISP's network carries more traffic. Shared infrastructure, particularly on cable plans, can slow your actual download speed significantly during busy periods.

Common questions

Operating systems report file transfer speeds in megabytes per second (MB/s), while ISPs sell plans in megabits per second (Mbps). There are 8 bits in a byte, so divide your Mbps by 8 to get MB/s. A 100 Mbps plan delivers up to 12.5 MB/s in file transfer terms.

If you are on Wi-Fi, switching to Ethernet is the most effective step. Pausing other downloads and streaming on your network frees up bandwidth. Using a download manager that opens multiple parallel connections can also improve speeds from servers that throttle single connections.

The file type itself does not affect speed. What matters is the file size, your connection speed, and the speed of the source server. Compressed files like ZIP archives download faster than uncompressed ones simply because they are smaller in bytes.

Related guides

Related tools

Calculator
Internet Speed Plan Calculator
Explainer
Speed Result Explainer
Guide
Router Placement Guide

Know your actual speed

Run a test to get the real number to put in the calculator above.

Start Speedtest