Security & Utilities
Download Time Calculator
Estimate ideal transfer time from a file size and advertised connection speed. This is a calculator, not a live speed test.
Estimate download time
Ideal estimated time
1 MB at 100 Mbps, using decimal units.
All calculations happen in this browser. KB, MB, GB and TB use decimal multiples; Kbps, Mbps and Gbps are bits per second.
How the estimate works
The calculator converts file bytes to bits, divides by the selected bits-per-second rate and formats the duration. For example, one decimal gigabyte contains eight gigabits before overhead.
Why real downloads take longer
The ideal estimate does not include protocol overhead, latency, congestion, Wi-Fi interference, retransmissions, server limits or competing traffic. Advertised access speed may also differ from throughput to a particular server.
Calculator, not measurement
No file is downloaded and no network performance is tested. Use the estimate for planning, then allow a margin for real-world conditions.
What this result means
The estimate divides file size by an idealized bit rate. Protocol overhead, congestion, Wi-Fi conditions, server limits and changing throughput normally make real downloads slower or variable.