Download-time calculator
Estimate how long a download will take, from the file size and your connection's download speed.
Result
Estimated download time
How to use this calculator
- Enter the file size — switch units if it's given in GB.
- Enter your download speed in Mbps (megabits per second) — check a speed test if you don't know it.
- Read the estimated download time.
Assumptions
- Assumes your full connection speed is available for the whole download, with no other traffic sharing it and no server-side bottleneck — real-world downloads are often slower than this ideal estimate.
Technical details: what the fields mean
- File size
fileSize - Size of the file or content being downloaded.
- Download speed
speedMbps - Your connection's download speed in Mbps — note this is megabits, not megabytes, per second.
Methodology
Time (seconds) = file size (megabits) ÷ speed (Mbps). File size in MB is converted to megabits by multiplying by 8, since 1 byte = 8 bits.
Worked example
5000MB file, 100Mbps connection
Inputs: fileSize=5000, speedMbps=100
Result: 6.7 minutes
Practical guidance
- A real download is often slower than this estimate due to network overhead, other devices sharing your connection, or the source server's own upload limits.
Common mistakes
- Confusing Mbps (megabits per second, how speed is advertised) with MB/s (megabytes per second, how file sizes and progress bars are usually shown) — divide Mbps by 8 to get MB/s.
FAQs
How long will a 5GB download take on 100Mbps?
About 6.7 minutes under ideal conditions — real-world speed is often somewhat lower.
Why is my download slower than my advertised speed?
Advertised speeds are usually in Mbps (megabits); actual download progress is normally shown in MB/s (megabytes) — divide by 8 to compare fairly. Network congestion and server limits also reduce real-world speed.