Developer tools
Download Time Calculator
Estimate how long a file download takes from file size and connection speed locally in your browser.
Enter the file size and the connection speed to estimate the download time with time equals file bits divided by bits per second. File sizes use decimal units (1 KB = 1000 bytes) and speeds use decimal bits (1 Mbps = 1000000 bps). The estimate runs locally in your browser; your values are not uploaded or stored.
Estimate a download time without uploading anything.
Enter the file size and the connection speed to see the estimated download time, the exact time in seconds, and the file size in bits. Everything runs locally in your browser, so your values are not uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
What does the download time calculator show?
Enter the file size up to 1000000 in B, KB, MB, GB, or TB plus the connection speed up to 1000000 in bps, Kbps, Mbps, or Gbps. The calculator returns the estimated download time as days, hours, minutes, and seconds, the exact time in seconds, minutes, and hours, the file size in bits, and the formula used. For example, a 100 MB file on a 100 Mbps connection takes about 8 seconds.
Which formula does the download time calculator use?
It uses time = (file size in bytes x 8 bits) / connection speed in bps, with decimal units: 1 KB = 1000 bytes and 1 Mbps = 1000000 bps. The file size converts to bits, then divides by the speed to give seconds, which are also shown as minutes and hours.
Which inputs are accepted?
Enter a file size greater than zero through 1000000 in the chosen size unit and a connection speed greater than zero through 1000000 in the chosen speed unit. Decimal values are accepted. Zero, negative numbers, non-numeric text, and values outside these limits show a clear error instead of a result, as does a file size above 1000000000000000 bytes.
Why can a real download take longer than the estimate?
The result is an ideal estimate at a constant speed. Protocol overhead, network congestion, Wi-Fi signal changes, server limits, and other traffic can slow a real download, so treat the estimate as a best-case duration.
Do my values leave my browser?
No. The calculation and copy action run locally in your browser. CodeASystem does not upload or store the values you enter.