Download Time Calculator
How long will this download take?
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Enter a file size and your internet speed to estimate the download time. It includes the bits-to-bytes factor (×8) that most quick guesses miss — the reason a '100 Mbps' connection doesn't download a 100 MB file in one second, but in eight.
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How Long Will a Download Take? — The Quick Answer
Divide the file size by the speed — but convert first. Internet speeds are in megabits per second (Mbps) while file sizes are in megabytes (MB), and there are 8 bits per byte, so multiply the file size by 8 before dividing.
Shortcut
time (sec) = (file size in MB × 8) ÷ speed in Mbps
Fact-Checking Claims You May Have Seen Online
A 100 Mbps connection downloads a 100 MB file in 1 second
False
100 Mbps means 100 megabits per second. A 100 MB file is 800 megabits, so it takes about 8 seconds — not 1. The ×8 factor is the single most common download-time mistake.
Time for a 1 GB file at different speeds
| Speed | 1 GB file |
|---|---|
| 10 Mbps | ~13 min 20 s |
| 50 Mbps | ~2 min 40 s |
| 100 Mbps | ~1 min 20 s |
| 500 Mbps | ~16 sec |
These are ideal figures. Real downloads are usually a little slower — overhead, Wi-Fi interference, server limits, and network congestion all reduce the effective speed below what your provider advertises.
How It Works
The Method
Bits, bytes, and the ×8 factor
Formula
time (s) = (file size in MB × 8) ÷ speed in Mbps
Variables
Megabits versus megabytes
Network speeds are measured in bits per second (lower-case b, Mbps). File sizes are in bytes (upper-case B, MB). One byte is 8 bits, so you multiply the file size by 8 to compare on the same scale.
In megabytes or gigabytes
Use the decimal figures (1 GB = 1,000 MB) that appear on download pages and drive labels. The calculator converts GB to MB internally.
Note: The estimate assumes a steady, full-speed connection. Real-world speeds are usually lower — Wi-Fi, distance from the router, server throttling, and other traffic all eat into the advertised maximum.
Last updated: October 5, 2026
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Frequently Asked Questions
How long does it take to download 1 GB?
At 100 Mbps, about 1 minute 20 seconds; at 50 Mbps, about 2 minutes 40 seconds; at 10 Mbps, around 13 minutes. The exact time depends on your sustained speed, which is usually a little below the advertised maximum.
Why isn't download time just file size divided by speed?
Because the units differ: internet speed is in megabits per second (Mbps) but file size is in megabytes (MB), and 1 byte = 8 bits. So you multiply the file size by 8 first: a 100 MB file needs 800 megabits transferred, which at 100 Mbps takes about 8 seconds, not 1.
Should I use my advertised or actual speed?
Use your actual sustained speed for a realistic estimate. Providers advertise peak speeds; a speed test (run when nothing else is using the connection) gives the real number. The estimate here is only as good as the speed you enter.
Does this work for uploads too?
Yes — the maths is identical. Just enter your upload speed (also in Mbps) instead of your download speed. Upload speeds on many home connections are much lower than download speeds, so uploads often take far longer.