Transfer time

How Long Does It Take to Upload 5 GB at 100 Mbps?

Uploading or downloading a 5 GB file at 100 Mbps takes about 6 minutes 40 seconds, assuming the full speed is sustained.

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

Upload or download time

6 min 40 s

100 Mbps is 12.5 MB/s. 5 GB is 5,000 MB, and 5,000 ÷ 12.5 = 400 seconds.

With 10% protocol overhead: about 7 minutes 20 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 5 GB and 100 Mbps; change either value and the answer and both reference tables update.

Open the calculator: 5 GB at 100 Mbps

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

What 5 GB actually is

Five gigabytes is roughly a single-layer DVD image (4.7 GB), a full 4K clip of a school play or a wedding speech straight off a phone, a modest Lightroom catalogue export or a small virtual-machine snapshot. Many email and cloud-drive free tiers stop well short of it, so it tends to be sent as a link rather than an attachment.

At 5 GB the difference between the advertised download speed and the real upload speed starts to show: a transfer that should take a few minutes on paper can take most of an hour on a typical cable or 4G upload. Checking your actual upload rate before promising a delivery time saves an awkward conversation later.

4K video (55 Mbps): about 12 minutes
1080p video (15 Mbps): about 44 minutes
RAW photos (40 MB each): about 125
25 MB email attachments: about 200

What 100 Mbps actually is

100 Mbps is the most common advertised home broadband speed and the number most people put into a calculator. Downloading at 100 Mbps is everyday; uploading at 100 Mbps means full fibre (FTTP), a symmetric business line or a lucky 5G cell. It moves 12.5 MB of file data a second.

Is 100 Mbps a realistic upload speed? Cable plans sold as 100 Mbps typically upload at 10–20 Mbps, so if you are sending rather than receiving on cable, the 10 Mbps and 25 Mbps figures are usually closer to what you will see. On fibre, 100 Mbps up is a modest, reliably sustained speed.

5 GB at other speeds, and other sizes at 100 Mbps

The first table keeps the file at 5 GB and changes the speed; the second keeps the speed at 100 Mbps and changes the file. Rows with their own write-up are linked. Every row is also written out as a sentence under "In words".

5 GB at neighbouring connection speeds
Connection speed	Time for 5 GB
25 Mbps	26 min 40 s
50 Mbps	13 min 20 s
100 Mbps	6 min 40 s
500 Mbps	1 min 20 s
1 Gbps	40 s

In words

5 GB at 25 Mbps takes about 26 minutes 40 seconds.
5 GB at 50 Mbps takes about 13 minutes 20 seconds.
5 GB at 100 Mbps takes about 6 minutes 40 seconds.
5 GB at 500 Mbps takes about 1 minute 20 seconds.
5 GB at 1 Gbps takes about 40 seconds.

Neighbouring file sizes at 100 Mbps
File size	Time at 100 Mbps
1 GB	1 min 20 s
2 GB	2 min 40 s
5 GB	6 min 40 s
10 GB	13 min 20 s
20 GB	26 min 40 s

In words

1 GB at 100 Mbps takes about 1 minute 20 seconds.
2 GB at 100 Mbps takes about 2 minutes 40 seconds.
5 GB at 100 Mbps takes about 6 minutes 40 seconds.
10 GB at 100 Mbps takes about 13 minutes 20 seconds.
20 GB at 100 Mbps takes about 26 minutes 40 seconds.

Why it usually takes longer than 6 minutes 40 seconds

Protocol overhead

The headline figure assumes every bit of the 100 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 5 GB at 100 Mbps is about 7 minutes 20 seconds with 10% overhead, 40 seconds longer. Quote that figure when someone is waiting for the file.

Upload is not download

The formula gives the same 6 minutes 40 seconds for an upload and a download, but the speed you should plug in is rarely the same. 100 Mbps 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 10 Mbps, which turns 6 minutes 40 seconds into about 1 hour 6 minutes for the same 5 GB. When you are the one sending, run a speed test and use the upload number.

Dropped connections

Over 6 minutes 40 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 5 GB at 100 Mbps?

About 6 minutes 40 seconds, the same as uploading, because the formula is file size divided by speed in both directions. The practical difference is that 100 Mbps 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 5 GB on a 100 Mbps plan, this estimate is usually close; if you are uploading, measure your upload speed first.

How long does 5 GB take at 100 Mbps with protocol overhead?

About 7 minutes 20 seconds once you allow 10% for TCP/IP headers, TLS and HTTP framing, which is 40 seconds longer than the raw 6 minutes 40 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 5 GB will arrive.

What if my connection only manages half of 100 Mbps while sending 5 GB?

Transfer time scales directly with speed: at 50 Mbps the same 5 GB takes about 13 minutes 20 seconds, and at 25 Mbps about 26 minutes 40 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 100 Mbps, and how does that give 6 minutes 40 seconds for 5 GB?

100 Mbps is 12.5 MB/s, because there are 8 bits in a byte. 5 GB is 5,000 MB, and 5,000 ÷ 12.5 = 400 seconds, which is 6 minutes 40 seconds. The calculator uses decimal units (1 GB = 1,000 MB); a file that Windows reports as 5 GB is about 7% larger in decimal terms and takes correspondingly longer.