How to use this tool
This tool works out how long a download will take, straight in your browser — nothing you type is sent anywhere. Enter the file size and your connection speed and it gives you the time in minutes and hours, with a second figure that adds a realistic buffer for overhead.
A note on speeds
Your speed test shows megabits per second (Mbps), but files are measured in megabytes (MB) — there's a factor of 8 between them. The tool handles the conversion for you, so you can just type what your speed test told you.
Why the 'realistic' number is higher
The raw calculation assumes your line is always at peak speed, which never happens. The realistic figure adds headroom for network congestion, protocol overhead and the server's own speed. If your first estimate feels optimistic, trust the second one.
Tip: if you're on a metered or capped connection, use the realistic number when you're deciding whether to download something large.