Transfer time

How Long Does It Take to Upload 100 GB at 1 Gbps?

Uploading or downloading a 100 GB file at 1 Gbps takes about 13 minutes 20 seconds, assuming the full speed is sustained.

By the HeftySend team Last updated 8 October 2026 Free, no sign-up

Upload or download time

13 min 20 s

1 Gbps is 125 MB/s. 100 GB is 100,000 MB, and 100,000 ÷ 125 = 800 seconds.

With 10% protocol overhead: about 14 minutes 40 seconds. Assumes the speed holds for the whole transfer.

Calculate your own

Different file size, a speed in MB/s or Gbps, or the 10% overhead switched on? The calculator opens pre-filled with 100 GB and 1 Gbps; change either value and the answer and both reference tables update.

Open the calculator: 100 GB at 1 Gbps

Works without JavaScript; the result is in the page when it loads.

What 100 GB actually is

One hundred gigabytes is about four hours of 4K footage, a full laptop user profile, a sizeable video-editing project with its proxies and renders, or a complete photo archive for a year. It is the largest transfer HeftySend accepts free with no account, so it is a natural reference point.

A 100 GB transfer is an overnight job on most home upload links and a lunchtime job on fibre. Because it spans hours, assume the connection will drop at least once and plan for it: a transfer that resumes from the last confirmed part finishes; one that does not may never finish on a flaky link.

4K video (55 Mbps): about 4 hours
1080p video (15 Mbps): about 15 hours
RAW photos (40 MB each): about 2,500
25 MB email attachments: about 4,000

What 1 Gbps actually is

1 Gbps (1,000 Mbps) is gigabit fibre, the top residential tier and a common office line. It moves 125 MB of file data a second, roughly the sustained read speed of a spinning hard drive, so the disk the file sits on can be the limit rather than the connection.

Is 1 Gbps a realistic upload speed? Holding a gigabit for an upload needs full fibre, gigabit Ethernet rather than Wi-Fi, a fast SSD and a receiving service that uploads in parallel parts, because a single TCP stream rarely sustains 1 Gbps over any distance. Cable plans sold as gigabit upload at 35–50 Mbps, twenty to thirty times slower.

100 GB at other speeds, and other sizes at 1 Gbps

The first table keeps the file at 100 GB and changes the speed; the second keeps the speed at 1 Gbps and changes the file. Rows with their own write-up are linked. Every row is also written out as a sentence under "In words".

100 GB at neighbouring connection speeds
Connection speed	Time for 100 GB
25 Mbps	8 h 53 min
50 Mbps	4 h 26 min
100 Mbps	2 h 13 min
500 Mbps	26 min 40 s
1 Gbps	13 min 20 s

In words

100 GB at 25 Mbps takes about 8 hours 53 minutes.
100 GB at 50 Mbps takes about 4 hours 26 minutes.
100 GB at 100 Mbps takes about 2 hours 13 minutes.
100 GB at 500 Mbps takes about 26 minutes 40 seconds.
100 GB at 1 Gbps takes about 13 minutes 20 seconds.

Neighbouring file sizes at 1 Gbps
File size	Time at 1 Gbps
10 GB	1 min 20 s
20 GB	2 min 40 s
50 GB	6 min 40 s
100 GB	13 min 20 s
1 TB	2 h 13 min

In words

10 GB at 1 Gbps takes about 1 minute 20 seconds.
20 GB at 1 Gbps takes about 2 minutes 40 seconds.
50 GB at 1 Gbps takes about 6 minutes 40 seconds.
100 GB at 1 Gbps takes about 13 minutes 20 seconds.
1 TB at 1 Gbps takes about 2 hours 13 minutes.

Why it usually takes longer than 13 minutes 20 seconds

Protocol overhead

The headline figure assumes every bit of the 1,000 Mbps carries file data. In practice TCP/IP headers, TLS and HTTP framing take 5–10% of the link, so a more realistic estimate for 100 GB at 1 Gbps is about 14 minutes 40 seconds with 10% overhead, 1 minute 20 seconds longer. Quote that figure when someone is waiting for the file.

Upload is not download

The formula gives the same 13 minutes 20 seconds for an upload and a download, but the speed you should plug in is rarely the same. 1 Gbps is usually the download speed of a plan; on an asymmetric cable, 4G or satellite link the upload side of that plan is often around 35 Mbps, which turns 13 minutes 20 seconds into about 6 hours 20 minutes for the same 100 GB. When you are the one sending, run a speed test and use the upload number.

Dropped connections

Over 13 minutes 20 seconds something can interrupt the transfer: a Wi-Fi roam, a laptop lid, a mobile hand-off between masts. A plain browser upload starts again from zero; a transfer that uploads in parts and resumes from the last confirmed part loses seconds. HeftySend uploads are resumable by default; the single button below takes you to the uploader.

Sending something big? Let it survive a dropped connection.

HeftySend uploads in parts and resumes from the last confirmed part, so a Wi-Fi blip or a sleeping laptop costs seconds, not the whole transfer. No account needed for transfers up to 100 GB.

Send up to 100 GB free

Frequently asked questions

How long does it take to download 100 GB at 1 Gbps?

About 13 minutes 20 seconds, the same as uploading, because the formula is file size divided by speed in both directions. The practical difference is that 1 Gbps is far more likely to be a real download speed than a real upload speed: plans advertise the download figure, and on cable, 4G and satellite the upload side is a fraction of it. If you are downloading 100 GB on a 1 Gbps plan, this estimate is usually close; if you are uploading, measure your upload speed first.

How long does 100 GB take at 1 Gbps with protocol overhead?

About 14 minutes 40 seconds once you allow 10% for TCP/IP headers, TLS and HTTP framing, which is 1 minute 20 seconds longer than the raw 13 minutes 20 seconds. Real transfers lose 5–10% of the link rate to that framing, so the overhead figure is the better one to quote when someone asks when 100 GB will arrive.

What if my connection only manages half of 1 Gbps while sending 100 GB?

Transfer time scales directly with speed: at 500 Mbps the same 100 GB takes about 26 minutes 40 seconds, and at 250 Mbps about 53 minutes 20 seconds. Wi-Fi, other devices on the network, a busy receiving server or a laptop on battery can each take a connection well below its headline figure, so a speed test taken right before you send is the only reliable input.

How many megabytes per second is 1 Gbps, and how does that give 13 minutes 20 seconds for 100 GB?

1 Gbps is 125 MB/s, because there are 8 bits in a byte. 100 GB is 100,000 MB, and 100,000 ÷ 125 = 800 seconds, which is 13 minutes 20 seconds. The calculator uses decimal units (1 GB = 1,000 MB); a file that Windows reports as 100 GB is about 7% larger in decimal terms and takes correspondingly longer.