How long will a 50 GB game take to download? Can you upload a 4 GB video before the meeting starts? The answer depends on two numbers that are, confusingly, measured in different units: file sizes in bytes and connection speeds in bits per second. This calculator converts both, allows for real-world network overhead, and shows how the same file would fare on other common connection speeds.
How to use the download time calculator
- Enter the file size and choose its unit: KB, MB, GB or TB (decimal) or KiB, MiB, GiB or TiB (binary).
- Enter the connection speed and its unit — usually Mbps for internet plans, or MB/s if you are reading a download manager.
- Set the network overhead: 10% is a sensible default, 0% gives the theoretical minimum.
- Read the estimated time on the tape. The table shows the same file at speeds from 10 Mbps to 2 Gbps.
Download time formula
| Unit | Bytes | Unit | Bits per second |
|---|---|---|---|
| 1 MB | 1,000,000 | 1 Mbps | 1,000,000 |
| 1 GB | 1,000,000,000 | 1 Gbps | 1,000,000,000 |
| 1 MiB | 1,048,576 | 1 MB/s | 8,000,000 |
| 1 GiB | 1,073,741,824 | 1 KB/s | 8,000 |
Worked example
A 50 GB game on a 300 Mbps connection with 10% overhead:
- Size in bits: 50 × 10⁹ bytes × 8 = 400 billion bits (400 gigabits).
- Effective speed: 300 Mbps × (1 − 0.10) = 270 Mbps, or 270 million bits per second.
- Time: 400,000,000,000 ÷ 270,000,000 ≈ 1,481 seconds, or about 24 minutes 41 seconds.
With no overhead it would take 400 ÷ 0.3 ≈ 1,333 seconds, or 22 minutes 13 seconds — the floor no real connection beats.
How long common downloads take
The table below assumes 10% overhead.
| File | 25 Mbps | 100 Mbps | 300 Mbps | 1 Gbps |
|---|---|---|---|---|
| 5 MB song | 1.8 s | 0.44 s | 0.15 s | 44 ms |
| 700 MB app | 4 min 9 s | 1 min 2 s | 21 s | 6.2 s |
| 4 GB HD movie | 23 min 42 s | 5 min 56 s | 1 min 59 s | 36 s |
| 50 GB game | 4 h 56 min | 1 h 14 min | 24 min 41 s | 7 min 24 s |
| 150 GB backup | 14 h 48 min | 3 h 42 min | 1 h 14 min | 22 min 13 s |
Understanding your connection
Advertised speeds are maximums
Federal Communications Commission broadband labels list typical download and upload speeds, which are often below the headline figure. Run a speed test on the device you will use, preferably over a wired connection, and enter that number for a realistic estimate.
Wi-Fi is often the bottleneck
A gigabit plan does not help if your laptop’s Wi-Fi link tops out at a few hundred megabits, or if walls and distance weaken the signal. Large downloads finish fastest over Ethernet.
Servers have limits too
Game stores, cloud drives and streaming services cap per-user speeds during busy periods. If a download is far slower than your speed test, the server — not your connection — is usually the limit.
To convert between storage units such as GB and GiB, use the data storage converter. For the hours and minutes between two clock times, the time duration calculator does the rest.
Frequently asked questions
Why is my download slower than my internet plan's speed?
Plans are sold in megabits per second, while files are measured in megabytes, and 1 byte = 8 bits, so a 100 Mbps plan moves at most 12.5 MB per second. On top of that, protocol overhead, Wi-Fi conditions, network congestion and the server's own limits typically shave off another 5–20%.
What is the difference between Mbps and MB/s?
Mbps (lowercase b) is megabits per second; MB/s (uppercase B) is megabytes per second. Divide Mbps by 8 to get MB/s: 300 Mbps is 37.5 MB/s. Browsers and download managers usually show MB/s.
Is a GB 1,000 or 1,024 megabytes?
Both conventions exist. A gigabyte (GB) in the SI sense is 10⁹ bytes, used by storage makers, macOS and ISPs. Windows reports sizes in binary units (2³⁰ bytes) but labels them GB; those are properly called gibibytes (GiB). The calculator offers both.
Does this work for uploads too?
Yes. Enter your upload speed instead. On many cable and DSL plans upload speed is a fraction of the download speed, so a large upload can take many times longer than the same download.
What overhead percentage should I use?
Around 5–10% for a good wired connection, 10–20% for typical Wi-Fi, and more for congested networks or distant servers. Use 0% for the theoretical best case.