Download Time Calculator
How long a download will take at your connection speed.
Estimate how long a file will take to download given its size and your connection speed, correctly converting between megabits and megabytes.
Megabits vs. megabytes
Internet providers advertise speed in megabits per second (Mbps), but file sizes are shown in megabytes (MB). There are 8 bits in a byte, so divide your Mbps by 8 to get the most megabytes you can download per second. A 100 Mbps plan gives at most 12.5 MB/s.
The formula
Download time (seconds) = file size in MB × 8 ÷ speed in Mbps
This calculator counts 1 GB as 1,024 MB, the way most computers report file sizes. Example: a 50 GB game on a 100 Mbps connection takes 50 × 1,024 × 8 ÷ 100 = 4,096 seconds — about 68 minutes.
Example download times
| Download | Size | 25 Mbps | 100 Mbps | 1 Gbps |
|---|---|---|---|---|
| HD movie | 5 GB | 27 min | 7 min | 41 sec |
| Phone or OS update | 8 GB | 44 min | 11 min | 66 sec |
| Large video game | 100 GB | 9.1 hours | 2.3 hours | 14 min |
These are best-case times at full speed.
Why real downloads take longer
- Wi-Fi: walls and distance from the router can cut your speed by half or more. A wired Ethernet connection usually gets much closer to your plan's speed.
- Shared connection: streaming and other devices in the house use part of your bandwidth.
- The server: the website or game store may send data slower than your connection can receive it, especially at busy times like a big game launch.
- Overhead: network protocols use a small share of the bandwidth, typically a few percent.
Run a speed test to find your real speed, then enter that number here for a more realistic estimate. To compare GB and GiB, use the file size converter.
Frequently asked questions
Why does my internet plan say "100 Mbps" but downloads seem slower?
Internet speeds are measured in megabits per second (Mbps), but file sizes are measured in megabytes (MB) — 1 byte = 8 bits, so a "100 Mbps" connection tops out around 12.5 MB/s in practice, before accounting for real-world overhead.
Why is the actual download often slower than this estimate?
This shows the theoretical time at your stated speed — real downloads are also affected by server speed, network congestion, and other devices sharing your connection.
What internet speed do I need?
As a rough guide, about 25 Mbps handles HD streaming on one or two devices, while households with several people streaming, gaming and working from home are more comfortable with 100–300 Mbps or more.