Download & Upload Time Calculator
Work out how long a file takes to download or upload at your connection speed - or the speed you need to finish in time. Handles Mbps vs MB/s, real-world overhead and the binary gigabytes Windows shows.
For an upload, enter your upload speed - on most cable and DSL plans it is far lower than the download speed.
Protocol and network losses. 5-10% is typical on a good wired line, more on Wi-Fi. Set 0 for the theoretical maximum.
Estimated time
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| Connection | Time |
|---|
Mbps is not MB/s. Internet plans are sold in megabits per second (Mbps). Browsers, Steam and download managers show megabytes per second (MB/s). A byte is eight bits, so a 100 Mbps line tops out at 12.5 MB/s - if your download shows 11-12 MB/s on a 100 Mbps plan, it is already running at full speed.
How to calculate download time
Download time is the file size divided by the speed, with both in the same unit. The quick way: convert the size to megabits (gigabytes × 8,000) and divide by your speed in Mbps. The answer is in seconds.
Example: 50 GB at 100 Mbps is 50 × 8,000 = 400,000 megabits. 400,000 ÷ 100 = 4,000 seconds, about 1 h 7 min. With 10% overhead it is closer to 1 h 14 min.
Upload time works the same way - just use your upload speed. To find the speed you need instead, divide the size in megabits by the seconds you have: 50 GB in one hour needs 400,000 ÷ 3,600 ≈ 111 Mbps of real throughput.
Why real downloads take longer
- Protocol overhead. TCP/IP headers, encryption and acknowledgements use a few percent of the line before any file data moves.
- Wi-Fi. The wireless hop is often the slowest link in the chain; a cable to the router can be much faster than the same plan over Wi-Fi.
- The other end. Servers and cloud services limit speed per connection and per user. At busy times the server, not your line, sets the pace.
- Distance. A single connection to a server on another continent rarely fills a fast line; transfers that use several connections in parallel get closer to the full speed.
- Binary gigabytes. Windows shows sizes in binary units (1 GB = 1,073,741,824 bytes), about 7% more than the decimal gigabyte that stores and providers use. Tick the box above when the size comes from File Explorer.
Download time for common file sizes
At full line speed with no overhead, decimal sizes. Add 5-10% for a typical real-world download.
| Size | 10 Mbps | 50 Mbps | 100 Mbps | 300 Mbps | 500 Mbps | 1 Gbps |
|---|---|---|---|---|---|---|
| 1 GB | 13 min 20 s | 2 min 40 s | 1 min 20 s | 27 s | 16 s | 8 s |
| 10 GB | 2 h 13 min | 26 min 40 s | 13 min 20 s | 4 min 27 s | 2 min 40 s | 1 min 20 s |
| 50 GB | 11 h 7 min | 2 h 13 min | 1 h 7 min | 22 min 13 s | 13 min 20 s | 6 min 40 s |
| 100 GB | 22 h 13 min | 4 h 27 min | 2 h 13 min | 44 min 27 s | 26 min 40 s | 13 min 20 s |
| 500 GB | 4 d 15 h | 22 h 13 min | 11 h 7 min | 3 h 42 min | 2 h 13 min | 1 h 7 min |
| 1 TB | 9 d 6 h | 1 d 20 h | 22 h 13 min | 7 h 24 min | 4 h 27 min | 2 h 13 min |
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