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Bandwidth and Upload Time Calculator

Calculate upload time from file size and connection speed, compare speed tiers, and estimate transfer windows for media files.

Why this tool is useful

Upload time is the question that decides whether a deadline is real. A 400 GB conform sent to a colorist, a day of camera originals going to a remote assistant, a master delivered the night before air: each one depends on a transfer window that is easy to underestimate and expensive to get wrong.

The arithmetic trips people up because file sizes are quoted in bytes and connection speeds in bits, a factor of eight that is easy to drop. This calculator handles that conversion, accepts speeds in Mbps, MB/s, or Gbps, and shows the same transfer across several speed tiers so you can see what a faster connection would actually buy you.

Enter a size or drop a file to measure it

Compare transfer times for one file against as many connection speeds as you want.

File size

Drop a local file here

Only the file size is read. Nothing uploads.

Compare speeds

Add connection speeds to see how long this file takes to transfer.

Mbps

17 minutes

to transfer 25 GB

Example use cases

  • Committing to a delivery time

    Check whether a master can reach a client before a deadline on the connection you have, before you promise the time.

  • Planning an overnight send

    Confirm a large handoff to color, VFX, or sound will complete inside the overnight window rather than still running at call time.

  • Comparing connection tiers

    See what upgrading from 100 Mbps to 1 Gbps does to a typical daily send before committing to the higher tier.

FAQ

Convert the file size to bits by multiplying gigabytes by 8,000 to get megabits, then divide by the connection speed in megabits per second to get seconds. A 100 GB file on a 100 Mbps connection is 800,000 megabits divided by 100, which is 8,000 seconds, or about two hours and thirteen minutes at full rate. The step people miss is the bits-to-bytes conversion: file sizes are quoted in bytes and connection speeds in bits, so leaving out the factor of eight makes the transfer look eight times faster than it is.
Several reasons compound. Advertised connection speeds are maxima, not guarantees, and upload speeds on consumer and many business plans are far lower than download. Protocol overhead consumes a few percent. Other traffic on the same link competes for bandwidth. Libraries with many small files spend significant time on per-file round trips rather than moving data. Destination-side throttling is common on general-purpose cloud storage services. Plan on 60 to 80 percent of the theoretical figure for a well-behaved transfer on a quiet link.
Mbps is megabits per second and MB/s is megabytes per second. One byte is eight bits, so 100 Mbps equals 12.5 MB/s. Internet service providers advertise in megabits, which produces a larger number, while file transfer applications usually display progress in megabytes. A transfer showing 12 MB/s on a 100 Mbps connection is running at full speed, not at a tenth of it, and that mismatch is a common source of unnecessary support calls.
For anyone sending media it usually does, and most connections are provisioned the other way around. Asymmetric plans commonly pair a fast download tier with an upload tier a tenth of the speed or worse, which is fine for streaming and terrible for delivering a master. If your work involves regularly pushing camera originals, conforms, or finished deliverables outward, a symmetric connection at a lower headline speed will often outperform a much faster asymmetric one.