Internet speed

How long does it take to download a 1 GB file?

The arithmetic is one line, but almost every estimate people make is eight times out because of the bit-versus-byte trap.

A 1 GB file takes about 80 seconds on a 100 Mbps connection. On 50 Mbps it is about 2.7 minutes, on 20 Mbps about 6.7 minutes and on 10 Mbps about 13.3 minutes. The reason it is 80 seconds and not 10 is that 100 Mbps means 100 megabits per second, which is 12.5 megabytes per second — and 1,000 ÷ 12.5 = 80.

Worked out 2026-09-10 (IST) · Decimal GB (1,000 MB), connection running at full advertised rate

Download time by file size and connection speed

Time to download, by connection speed
Speed	100 MB	500 MB	1 GB	5 GB	25 GB	50 GB
5 Mbps	2.7 min	13.3 min	26.7 min	2.2 h	11.1 h	22.2 h
10 Mbps	80 s	6.7 min	13.3 min	66.7 min	5.6 h	11.1 h
20 Mbps	40 s	3.3 min	6.7 min	33.3 min	2.8 h	5.6 h
40 Mbps	20 s	1.7 min	3.3 min	16.7 min	83.3 min	2.8 h
50 Mbps	16 s	80 s	2.7 min	13.3 min	66.7 min	2.2 h
100 Mbps	8 s	40 s	80 s	6.7 min	33.3 min	66.7 min
200 Mbps	4 s	20 s	40 s	3.3 min	16.7 min	33.3 min
300 Mbps	3 s	13 s	27 s	2.2 min	11.1 min	22.2 min
500 Mbps	2 s	8 s	16 s	80 s	6.7 min	13.3 min
1000 Mbps	1 s	4 s	8 s	40 s	3.3 min	6.7 min

Read the row you actually get, not the one you pay for. Run a speed test on a wired connection and use the measured figure. Advertised rates are “up to” figures and Wi-Fi commonly delivers half of one.

What 1 GB actually holds

Roughly what fits in 1 GB
Content	Typical size	Fits in 1 GB
Photo from a phone camera	4 MB	about 250
Song, 320 kbps MP3	8 MB	about 125
Episode, 1080p streaming	900 MB	about 1
Film, 1080p download	2 GB	half of one
Hour of 4K streaming	7 GB	about 9 minutes
Page of plain text	2 KB	about 500,000

The formula

seconds = file size in megabytes × 8 ÷ speed in Mbps

for a file in GB: seconds = GB × 8,000 ÷ Mbps

minimum speed for a target time: Mbps = GB × 8,000 ÷ seconds

Check your own numbers

Convert any file size between bytes, MB, GB and TB before you do the division.

Data Storage ConverterBytes to KB, MB, GB, TB and PB, in binary and decimal.

Frequently asked

Why is my download slower than this table says?

Three usual causes, in order of likelihood. Wi-Fi: a 2.4 GHz link or a wall between you and the router routinely halves the rate. The source server: a free download mirror may cap each connection well below your line speed. Shared load: other devices on the same connection, or peak-hour contention on your ISP's local segment. If a wired speed test hits the advertised rate but downloads do not, the bottleneck is not your connection.

Does the 1024 vs 1000 difference matter here?

A little. If your 1 GB is a binary gigabyte (1,073,741,824 bytes, which is what Windows means by GB) the download takes 7.4 per cent longer than the table shows - 86 seconds instead of 80 on a 100 Mbps line. For estimating, the difference is inside the noise; for a 50 GB game it is about five extra minutes.

How long does a 4 GB movie take on 5G?

A typical Indian 5G connection delivers 100 to 300 Mbps in real use, so 4 GB takes between 1.8 and 5.3 minutes. On a good mid-band 5G cell touching 500 Mbps it is about 64 seconds. The limiting factor on mobile is usually the data allowance rather than the speed.

What speed do I need to download 1 GB in under a minute?

At least 134 Mbps. One gigabyte is 8,000 megabits, and 8,000 divided by 60 seconds is 133.3 Mbps, so a 150 Mbps plan clears it with margin and a 100 Mbps plan does not.

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