File Transfer Time Calculator
Time to send or receive a file over a connection, allowing for real-world overhead.
Results
Minutes
7.84
min
Seconds
470.6
s
Hours
0.131
h
Effective transfer rate
10.625
MB/s
What this tool does
Advertised speeds are theoretical maximums measured in bits, while files are in bytes — a factor of eight straight away. The efficiency figure covers protocol overhead and shared capacity; eighty to ninety percent is realistic on a good connection, much less on a busy one.
Formula
time = size × 8 ÷ speed ÷ efficiency
Variables
| Symbol | Meaning | Unit |
|---|---|---|
sz | File size | GB |
sp | Connection speed | Mbit/s |
ef | Efficiency | % |
T | Minutes | min |
TS | Seconds | s |
TH | Hours | h |
MB | Effective transfer rate | MB/s |
Worked example
- File size5 GB
- Connection speed100 Mbit/s
- Efficiency85 %
- Minutes7.84 min
- Seconds470.6 s
- Hours0.131 h
- Effective transfer rate10.625 MB/s
Limitations
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
- US and imperial (UK) units with the same name are not the same size. Check which system your figures come from.
Frequently asked questions
Why is my 100 Mbps line not giving 100 MB per second?
Because connections are sold in megabits and files are measured in megabytes, and there are eight bits in a byte. A 100 Mbit/s line therefore tops out around 12.5 MB/s, and protocol overhead, contention and disk speed take a further slice — which is what the efficiency figure accounts for.