Computers & Laptops

Upload Time Calculator

How long an upload takes at your upload speed - which on most connections is much lower than the download figure.

4 inputs Free, no sign-up

Your figures

The upload figure from a speed test, not the download one. On cable and DSL they are very different numbers; on fibre they are often similar.

Try an example

Result

Your result

Enter your figures and the result appears here.

Estimates only. Rates, fees and specifications change. Confirm against the official source before you rely on a figure — see our disclaimer.

About this calculator

Upload is usually the slower half of a connection, and it is the half nobody quotes. A line advertised at 100 Mbps may upload at 20, or at 10, and the backup you are pushing to the cloud runs at that figure rather than the headline one.

How to use this calculator

  1. Enter the size of what you are uploading.
  2. Run a speed test and use the upload number it reports.

The formula

Time = File size in bytes / Upload speed in bytes per second

1 Mbps = 125,000 bytes per second
SymbolMeaningUnit
File size How much you are sending GB
Speed Your upload speed Mbps

Worked example

A 2 GB video on a 20 Mbps upload:

2 GB      = 2,000,000,000 bytes
20 Mbps   = 2,500,000 bytes per second
Time      = 800 seconds = 13 minutes 20 seconds

The same file would download in under three minutes on a 100 Mbps line.

Notes and limits

  • Cable and DSL connections are asymmetric by design: upload is often a fifth or a tenth of download. Fibre is usually much closer to symmetric.
  • A large upload saturates the line and makes everything else on the connection feel slow, which is why backup software often has a rate limit.
  • Cloud services sometimes throttle uploads independently of your connection.
  • First backups are the painful ones. Once the bulk is up, incremental uploads are small.

What this calculation assumes

  • The upload speed is assumed sustained for the whole transfer.
  • Overhead and any service-side throttling are not modelled.

Frequently asked questions

Why is my upload so much slower than my download?

Most consumer connections are asymmetric by design - the technology allocates more capacity to download because that is what most people use. Fibre connections are often much closer to symmetric.

How long will it take to upload 100 GB to cloud backup?

At 20 Mbps, roughly eleven hours of continuous uploading. At 5 Mbps, nearly two days. This is why first backups are usually left running overnight for several nights.

Can I speed up an upload?

Not beyond the line's capacity. What helps is uploading when nothing else is using the connection, using a wired link instead of Wi-Fi, and compressing what you send.

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