Why is the real download slower?

ISP speeds are 'up to' and shared, plus TCP overhead (~5-10%), server limits, and contention. Real-world is typically 70-90% of advertised speed.

How is time computed?

Time = file size in bytes ÷ (speed in Mbps × 1,000,000 ÷ 8). The ÷8 converts bits to bytes.

US average broadband: ~150 Mbps. Mobile 4G: 20-50 Mbps. 5G: 100-1000 Mbps. Gigabit fiber: 940 Mbps. Dial-up: 56 Kbps.

Yes, but use your upload speed (typically 10-50% of download speed on most plans). Fiber often has symmetric upload = download.

No — all calculations happen in your browser.

Estimate download time for any file size and connection speed.

100% private — no uploads Unit & Data ConvertersFree & unlimited Read tutorial

Watch a quick simulation of this tool in action — no file needed.

Follow these steps — everything happens instantly in your browser.

1
Step 1. Enter the file size (MB, GB, or TB).
2
Step 2. Set your internet connection speed in Mbps.
3
Step 3. See the estimated download time and a comparison across common speeds.

Everything you might want to know about download time calculator.

Convert between bit, byte, KB/KiB, MB/MiB, GB/GiB, TB/TiB.

Convert between B, KB, MB, GB, TB & PB — 1024-based.

Compute PPI, physical dimensions, and area from resolution + diagonal.

Length, weight, temperature, area, volume & speed — all in one.