Calculate download and upload time for any file size based on connection speed
File Size
Connection Speed
Estimated transfer time
1 min 26 s
1.00 GB @ 100 Mbps
Effective speed
100.0 Mbps
Transferred in 1 min
715.26 MB
Transferred in 1 hour
41.91 GB
Speed Reference
| Connection | Typical speed | 1 GB takes |
|---|---|---|
| 3G | 10 Mbps | 14 min 19 s |
| 4G LTE | 50 Mbps | 2 min 52 s |
| 5G | 300 Mbps | 29 seconds |
| ADSL / DSL | 25 Mbps | 5 min 44 s |
| Cable 200 Mbps | 200 Mbps | 43 seconds |
| Fiber 1 Gbps | 1 Gbps | 9 seconds |
| USB 2.0 | 480 Mbps | 18 seconds |
| USB 3.0 | 5 Gbps | 2 seconds |
* Real-world speeds vary. 1 GB = 1,073,741,824 bytes.
This bandwidth calculator computes how long it takes to transfer a file given a connection speed. Enter the file size and your internet or network speed, and the tool instantly shows the estimated transfer time — from milliseconds for tiny files on fast connections to days for huge archives on slow links.
How to Use
- 1Enter the file size and choose the unit (B, KB, MB, GB, or TB).
- 2Enter the connection speed and choose Kbps, Mbps, or Gbps.
- 3Optionally tick the 10% protocol overhead checkbox for a realistic TCP/IP estimate.
- 4The transfer time updates instantly as you type.
- 5Use the preset buttons to quickly test against common connection speeds.
Frequently Asked Questions
Why do file sizes use 1024 and network speeds use 1000?
File sizes follow binary prefixes (1 KB = 1024 bytes) while network speeds use decimal prefixes (1 Mbps = 1,000,000 bits). This calculator converts correctly between both conventions.
What does the 10% protocol overhead mean?
TCP/IP headers and acknowledgments consume roughly 5–10% of raw bandwidth. Enabling this option reduces the effective speed by 10% to give a more realistic estimate for real-world transfers.
How do I convert from my ISP's Mbps to MB/s?
Divide by 8: 100 Mbps = 12.5 MB/s. ISPs advertise in megabits per second while download managers show megabytes per second.