Download Time Calculator
Calculate how long a download will take, given the file size and your connection speed.
- Free to use
- No registration required
- Works on all devices
- Last updated
- 13-09-2026
Your result
6m 40s
Download time
AI explanation
Formula
Download time = (file size in bits) ÷ (connection speed in bits per second)Worked example
5GB file at 100 Mbps
| Field | Value |
|---|---|
| File size | 5 |
| File size unit | GB |
| Connection speed | 100 |
| Speed unit | Mbps |
| Download time | 6m 40s |
| Download time (seconds) | 400 |
Assumptions
- Uses decimal (SI) units throughout — 1 MB = 1,000,000 bytes, 1 Gbps = 1,000 Mbps — matching how ISPs advertise speeds.
- Assumes the full advertised speed is sustained for the entire download with no interruptions or competing traffic — real-world downloads are usually slower.
Frequently asked questions
Why is my actual download slower than this calculation?
Real connections rarely sustain their full advertised speed due to network overhead, other devices sharing the connection, server-side limits, and Wi-Fi signal quality — this calculator shows the theoretical best case.
Why is the unit Mbps and not MB/s?
Internet speeds are conventionally advertised in megabits per second (Mbps), while file sizes are shown in megabytes (MB) — there are 8 bits per byte, so this matters for accurate time estimates.
Can I use this for streaming instead of downloading?
This estimates a full-file download time — for streaming, what matters is whether your speed exceeds the stream's bitrate, not the total file size.
Why is my upload speed so much lower than my download speed?
Most home internet plans (especially cable and DSL) are asymmetric by design, prioritizing download bandwidth since most home usage (browsing, streaming) is download-heavy. Fiber connections are more likely to offer symmetric speeds.
Where do I find my actual upload speed?
Run a speed test (many free options are available online) — check the "upload" result specifically, not the download result.
Why is a 1TB transfer over Gigabit still slow?
Even at a full 1 Gbps (1,000 Mbps), transferring 1 terabyte of data (8 trillion bits) theoretically takes over 2 hours — real-world transfers are often slower still due to overhead and disk I/O limits.
Does this account for compression or deduplication?
No — enter the actual size of data that will move across the network. If your transfer tool compresses or deduplicates data first, use that reduced size instead.