Download Time Calculator
Estimate how long a file takes to download at a given connection speed, allowing for protocol overhead.
Your inputs
Results
Estimated download time
6 min 58 s
- In seconds
- 417.78
- Effective throughput
- 90 Mbps
- Time at full line rate (no overhead)
- 6 min 16 s
≈Estimate based on the stated model and assumptions
What this calculator does
Advertised speeds are in bits per second while files are measured in bytes, and real throughput is lower than the line rate.
Formula and method
Time = file size × 8 ÷ (speed × (1 − overhead))
Worked example
Calculated by this tool with its default inputs:
Inputs
- File size: 4.7
- Size unit: GB
- Connection speed: 100
- Speed unit: Mbps
- Protocol overhead and real-world loss: 10 %
Results
- Estimated download time: 6 min 58 s
- In seconds: 417.78
- Effective throughput: 90 Mbps
- Time at full line rate (no overhead): 6 min 16 s
How to read the results
Compare the realistic time with the ideal time at full line rate.
Assumptions and limitations
- Server limits, Wi-Fi and network congestion can slow downloads further.
Questions
Why multiply by 8?
There are 8 bits in a byte, and speeds are quoted in bits.
Methodology and verification
- Result type
- Estimate based on the stated model and assumptions
- Formula version
- 1.0
- Automated verification
- 3 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
- Editorial review
- Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.
Privacy
Everything you enter is calculated in this browser and is not sent to Numerith or anyone else. Inputs are added to a share link only if you choose to include them. Privacy policy