Download Time Calculator
How long a file takes at your connection speed.
Reviewed by the Calculation Machine team · Updated 24 October 2026 · How we check our maths
Your values
ⓘ Live results
- Download time
- 8m 1s
- Effective speed
- 80 Mbps (10 MB/s)
- Total data
- 4813 MB
- Time at full advertised speed
- 6.4 minutes
Quick answer
Download time = file size in bits ÷ connection speed in bits per second. Because internet speeds are quoted in megabits and file sizes in megabytes, multiply the size in MB by 8 before dividing by the speed in Mbps. A 4.7 GB file on a 100 Mbps connection running at 80% efficiency takes about 8 minutes; at the full advertised speed it would take 6.4 minutes.
What the Download Time calculator does
This calculator estimates how long a file takes to download from its size in gigabytes and your connection speed in megabits per second. It shows the expected time after a real-world efficiency allowance, the effective speed in both Mbps and MB/s, and the best-case time at your full advertised speed. It works for any file: a game update, a 4K film, a backup restore or a large work upload.
Your actual speed is almost always below the plan's headline figure. Wi-Fi signal, other devices on the network, the server's own speed limit and protocol overhead all take a share, which is what the efficiency field allows for. Running a speed test on the device you will download to gives a better input than the number on your bill.
To convert between storage units first, use the data storage converter. If you are working out how big a video will be before you download or upload it, start with the video file size calculator.
The formula
Time (s) = size (GB) × 1,024 × 8 ÷ (speed (Mbps) × efficiency)
| Symbol | Meaning | Unit |
|---|---|---|
| size | File size as shown by your computer or the store page | GB |
| 1,024 | Megabytes per gigabyte, as Windows and most download clients count them | MB per GB |
| 8 | Bits per byte | bits |
| speed | Connection speed in megabits per second | Mbps |
| efficiency | Share of the advertised speed you actually get | % |
The bits-per-byte conversion is fixed; the only judgment is the efficiency figure. The calculator treats 1 GB as 1,024 MB, matching how operating systems report file sizes, so for a size quoted in decimal gigabytes (1 GB = 1,000 MB) the estimate runs about 2.4% long. Upload time uses the same formula with your upload speed, which on cable and DSL plans is often much lower than the download speed.
Worked examples
Large game on fiber
A 100 GB game download on a 500 Mbps plan, with the console getting about 85% of the plan speed over a wired connection.
Inputs
- File size100 GB
- Connection speed500 Mbps
- Real-world efficiency85 %
Result
- Download time32m 8s
- Effective speed425 Mbps (53.13 MB/s)
- Total data102400 MB
- Time at full advertised speed27.3 minutes
About 32 minutes. Game stores often limit per-download speed at launch time, so a slower result on release day usually means busy servers rather than your connection.
Video file on a slow connection
A 500 MB (0.5 GB) video on a 10 Mbps rural connection at 80% efficiency.
Inputs
- File size0.5 GB
- Connection speed10 Mbps
- Real-world efficiency80 %
Result
- Download time8m 32s
- Effective speed8 Mbps (1 MB/s)
- Total data512 MB
- Time at full advertised speed6.8 minutes
About 8.5 minutes, at an effective 1 MB/s. On slow links every other device streaming at the same time cuts directly into this, so pause other traffic for big downloads.
Restoring a cloud backup on gigabit
Restoring 150 GB of photos from cloud backup over a 1 Gbps (1,000 Mbps) connection at 90% efficiency.
Inputs
- File size150 GB
- Connection speed1000 Mbps
- Real-world efficiency90 %
Result
- Download time22m 45s
- Effective speed900 Mbps (112.5 MB/s)
- Total data153600 MB
- Time at full advertised speed20.5 minutes
About 23 minutes in theory. In practice, backup services and the speed of the destination drive often cap transfers well below gigabit, so allow several times longer.
Mbps vs MB/s: why your download looks 8× slower
Internet plans are sold in megabits per second (Mbps), while browsers, Steam and file managers usually show progress in megabytes per second (MB/s). Divide Mbps by 8 to get MB/s. A 100 Mbps line maxes out at 12.5 MB/s, so seeing 11–12 MB/s in a download window means the connection is working as it should.
| Plan speed | Max MB/s | 50 GB download |
|---|---|---|
| 10 Mbps | 1.25 MB/s | 11h 22m |
| 25 Mbps | 3.1 MB/s | 4h 33m |
| 100 Mbps | 12.5 MB/s | 1h 8m |
| 300 Mbps | 37.5 MB/s | 22m 45s |
| 500 Mbps | 62.5 MB/s | 13m 39s |
| 1 Gbps | 125 MB/s | 6m 50s |
Choosing a realistic efficiency figure
- 90–95%: wired Ethernet connection to a fast server, nothing else using the network.
- 70–85%: good Wi-Fi in the same room as the router, or a busy household.
- 40–60%: Wi-Fi through walls or floors, older routers, or a crowded evening network.
- Below 40%: distant Wi-Fi, mobile data with weak signal, or a server that throttles each user.
The quickest fix for slow large downloads is usually a cable: plugging in removes most Wi-Fi losses. A speed test from the same device shows which band you are in.
File download time for different file types
The calculator handles any file once you know its size. Typical sizes to plug in: a high-definition movie stream is a few gigabytes per hour, a 4K film can be 15–25 GB or more, a modern console game is often 50–150 GB, and a phone photo is a few megabytes. Enter megabytes as a fraction of a gigabyte (500 MB = 0.5 GB). For network capacity planning — how many users or streams a link can carry rather than how long one file takes — use the bandwidth calculator.
How to use the Download Time Calculator
- 1Enter the file size in GB from the store page, download dialog or file properties. Divide MB by 1,000 for small files.
- 2Enter your connection speed in Mbps — ideally from a speed test on the device you will use.
- 3Set the efficiency: about 90% for wired connections, 70–80% for good Wi-Fi.
- 4Read the estimated time, the effective speed in MB/s, and the best case at full speed.
Frequently asked questions
How long does it take to download 1 GB?
At 100 Mbps, 1 GB (counted as 1,024 MB) takes about 82 seconds at full speed. At 25 Mbps it is about 5.5 minutes, and on gigabit fiber around 8 seconds.
How do I convert Mbps to MB/s?
Divide by 8, because a byte is 8 bits. 200 Mbps is 25 MB/s and 1,000 Mbps is 125 MB/s.
Why is my download slower than my internet speed?
Wi-Fi losses, other devices sharing the connection, protocol overhead and the server's own limits all reduce what you get. Many downloads also start slowly and speed up, so short downloads rarely reach full speed.
Does this work for upload time?
Yes. Enter your upload speed instead of your download speed. On many cable and DSL plans upload is a small fraction of download speed, so uploads of the same file take much longer.
Is a GB 1,000 or 1,024 MB?
Both are used. Storage makers count 1 GB as 1,000 MB; Windows counts 1,024 (strictly a gibibyte). This calculator uses 1,024, so it gives slightly longer, more cautious estimates.
References
- SI Brochure: The International System of Units (prefixes kilo, mega, giga) — Bureau International des Poids et Mesures (BIPM)
- IEC 80000-13, Quantities and units — Information science and technology — International Electrotechnical Commission
- Broadband speed guide — Federal Communications Commission
About this calculator
- Built and reviewed by the Calculation Machine team · How we build and test calculators
- Last reviewed: October 24, 2026
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