Upload time calculator

How upload time is calculated

The maths is the same as for downloads: convert the size to bits and divide by the upload rate.

seconds = size in GB × 8,000 ÷ upload speed in Mbps

With the real-world efficiency option ticked, the speed is first multiplied by the efficiency (90% by default). The presets are chosen for uploading: speeds of 5, 10, 20, 50, 100 and 500 Mbps, and sizes of 100 MB, 1 GB, 5 GB, 25 GB and 100 GB.

The reason this deserves its own calculator is asymmetry. Cable and DSL plans often pair a fast download with a much slower upload. The FCC's 2024 broadband benchmark, for example, is 100 Mbps down and 20 Mbps up: a 5:1 ratio. Fibre plans are more often symmetrical. Check your own upload figure on a speed test before you rely on a plan's headline number.

Worked examples

• A 25 GB video project at 20 Mbps. 25 × 8,000 ÷ 20 = 10,000 seconds, or 2 hours 46 minutes 40 seconds. The same file downloads in about 33 minutes 20 seconds at 100 Mbps.
• A first cloud backup of 100 GB at 20 Mbps. 40,000 seconds, or 11 hours 6 minutes 40 seconds at full speed. At 90% efficiency it is about 12 hours 21 minutes, which is why large first backups are best left running overnight.
• A 1 GB video at 10 Mbps. 800 seconds, or 13 minutes 20 seconds.
• A 100 MB batch of photos at 5 Mbps. 160 seconds.

Assumptions and limits

The estimate assumes the upload has the line to itself. Video calls, cloud cameras and other devices all share the same upload, and a saturated upload also slows browsing and calls for everyone in the home, because requests and acknowledgements have to squeeze through the same link. Many backup and sync apps let you cap their upload rate; leaving a margin keeps calls usable while a big upload runs.

Upload services may also limit speed on their side or process files after upload, which the calculator cannot know. Sizes use decimal units; if your editor or file manager shows GiB, pick the matching unit or add about 7.4%.

Planning a regular upload

For uploads that recur, such as nightly backups, think in volume per day. The data transfer calculator shows how much a given speed moves in a set window, and the upload speed calculator works out the upload a household needs for streaming, calls and cameras together. Upload vs download speed explains why the two figures differ, and the download time calculator covers the receiving side.