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Download Time Calculator How long will it take?

Enter the file size and your connection speed to get the transfer time, with megabits, megabytes and gibibytes converted for you.

Sizes in MB, GB, TB, GiB or TiB
Speeds in Mbps, Gbps or MB/s
Adjust for the share of your plan speed you really get

Built by Marcus Reed, laptop and desktop repair technician

Download time calculatortime = size × 8 ÷ speed

File sizeGame, backup, video, ISO

Your speedPlan speed or a speed test result

Share of that speed you get100% = a perfect line. Speed test ÷ plan gives your real share

Estimated time

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This is the time at a steady speed with nothing else using the connection. Uploads use the same math: enter your upload speed. Real downloads also depend on the server and on Wi-Fi, so a slower result than this is common.

8 bitsin one byte
12.5 MB/swhat a 100 Mbps line moves at full speed
44 minfor 100 GB at 300 Mbps
1,073,741,824bytes in one GiB (NIST)

Quick answer

Download time is the file size in bits divided by your speed in bits per second. A 100 GB game at 300 Mbps takes about 44 minutes; at 100 Mbps it takes about 2 hours 13 minutes. Enter your own numbers above and the calculator handles the conversions between megabits, megabytes, gigabytes and gibibytes.

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The formula, and the two unit traps

Time in seconds equals file size in bytes, times 8, divided by speed in bits per second. Most wrong estimates come from mixing up two pairs of units.

Bits and bytes. Internet speeds are sold in megabits per second (Mbps). File sizes are counted in bytes. One byte is 8 bits, so a 300 Mbps connection moves at most 37.5 megabytes per second. If a download window shows MB/s, multiply by 8 to compare it with your plan.

GB and GiB. A gigabyte (GB) is 1,000,000,000 bytes. A gibibyte (GiB) is 1,073,741,824 bytes, which is 2 to the 30th power; the binary prefixes are defined by the IEC and explained on NIST’s page on prefixes for binary multiples. Some software labels binary sizes with the decimal name, so if a size looks about 7% smaller than you expected, pick GiB in the calculator.

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Common download times at a glance

Calculated at a steady speed with decimal gigabytes:

File	100 Mbps	300 Mbps	1 Gbps
5 GB video or app	6m 40s	2m 13s	40s
50 GB game	1h 6m 40s	22m 13s	6m 40s
150 GB game	3h 20m	1h 6m 40s	20m
1 TB first cloud backup (upload)	22h 13m 20s	7h 24m 27s	2h 13m 20s

03 / 05

Is my download speed normal? Reading MB/s against your plan

Steam, most browsers and many game launchers show download speed in megabytes per second, while the plan is sold in megabits. Steam Support’s own article on slow downloads makes the point: multiply Steam’s figure by 8 to compare it with what your provider advertises, or switch Steam to bits under Settings, then Downloads. Here is what a healthy readout looks like on common plans:

Plan	Most it can show	At 90% of plan	At 70% of plan
100 Mbps	12.5 MB/s	11.3 MB/s	8.8 MB/s
300 Mbps	37.5 MB/s	33.8 MB/s	26.3 MB/s
500 Mbps	62.5 MB/s	56.3 MB/s	43.8 MB/s
1 Gbps	125 MB/s	112.5 MB/s	87.5 MB/s

So a game showing 33 MB/s on a 300 Mbps plan is using almost all of the line. A reading of 3 MB/s on the same plan is a real problem, and the checklist below is where to start. To see what a slower real-world speed does to your own download, lower the “share of that speed you get” field in the calculator.

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Download slower than expected? Check in this order

Units first. Convert the readout with the table above. Many “my download is eight times too slow” threads on the Steam forums end with the same answer: MB/s read as Mbps.
Test the line now, on the same device. Run a speed test right before the download. If the test is also slow, the problem is your connection or Wi-Fi, not the download.
Take Wi-Fi out of it. Plug the computer into the router with a cable and download again. A big jump means the bottleneck is the wireless link, and fixing slow Wi-Fi in one room is the next step.
Look at the server side. When the speed test is fast but one download is slow, the sender is the limit. In Steam, Steam Support points to the download region setting under Settings, then Downloads; trying another region or another time of day is the usual fix.
Big game update crawling? Watch the drive, not the network. Open Task Manager during the update. If the disk sits at 100% while network use is low, the download is waiting on storage: the launcher is rebuilding large game files on a slow hard drive. In an r/Steam thread about exactly this, the top answer pointed at free space: “some can require 1-2x the size of the game in extra available space to install a patch.” Freeing space or moving the game to an SSD helps more than a faster plan.
Check for limits and competition. Launchers and backup apps often have a bandwidth cap in their settings, and other people streaming or backing up share the same line. The internet speed calculator shows how much of your plan a busy household already uses.

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Planning a big upload

The first full backup to a cloud service is an upload, and upload speeds on home plans are often a fraction of download speeds. A terabyte at 20 Mbps up is more than four days of continuous uploading, which is why it helps to start a first backup overnight and leave the computer awake. Unlimited cloud backup covers what the plans include and what the services say about that first upload.

FAQ

Questions people ask

How long does a 100 GB download take at 300 Mbps?

About 44 minutes 27 seconds at a steady 300 Mbps. 100 GB is 800,000 megabits, and 800,000 divided by 300 is 2,667 seconds.

Why is my download slower than my plan speed?

The plan speed is the most the line is sold to carry. The server you download from, Wi-Fi signal, other people on the network and the plan’s own limits all pull the real number down. Run a speed test right before a big download and enter that number instead.

What is the difference between Mbps and MB/s?

Mbps is megabits per second and MB/s is megabytes per second. One byte is 8 bits, so 100 Mbps moves at most 12.5 MB/s. Internet plans are sold in Mbps; download windows often show MB/s.

Does this work for uploads?

Yes. The math is the same in both directions. Enter your upload speed from a speed test, which is usually much lower than the download speed on home plans.

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