Work out how long a download takes, how big a video is, which bitrate fits a size limit, and the storage for cameras, audio and streaming, with bits and bytes explained.
Download time is the file size in bits divided by the speed in bits per second. ISPs advertise in Mbps (megabits per second), but files and browsers use MB (megabytes). Since 1 byte is 8 bits, 100 Mbps equals 12.5 MB/s and 1 Gbps equals 125 MB/s. A 1 GB file downloads in 80 seconds at 100 Mbps if the connection delivers its full speed, which is why downloads feel eight times slower than the number on the plan. Then there is decimal versus binary. A decimal 1 GB is 1,000,000,000 bytes; 1 GiB is 1,073,741,824 bytes, about 7.4% more. Some systems, such as Windows, show GiB with the GB label. The tool lets you pick the base and shows the time in both: 1 GB at 100 Mbps takes 80 s, and 1 GiB takes 85.9 s. Mbps is always decimal. The speed that reaches the file is usually lower than the contracted one: TCP and IP headers, Wi-Fi, the origin server and the time of day all weigh in. On Ethernet with IPv4 and TCP the theoretical ceiling is about 95% (1,460 useful bytes in each 1,538-byte frame on the wire). By default the calculator uses 100%, the theoretical value; the 90% and 80% shortcuts are your own assumptions, not measurements. For video, size is (video bitrate + audio bitrate) times duration, divided by 8: 10 minutes at 8 Mbps is 600 MB. The inverse mode answers how much bitrate fits a limit, such as the 25 MB of a Gmail attachment, and compares the result with YouTube's upload recommendation. There is also storage for cameras and recordings (8 cameras at 4 Mbps, 24 hours a day, 30 days take 10.368 TB), audio size by format (WAV at 44.1 kHz, 16 bit, stereo is 1,411.2 kbps) and streaming data usage. The YouTube bitrates come from the official upload and live streaming pages, checked on 2026-10-06, and are recommendations, not rules. Platforms change these values over time.
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<iframe
src="https://jkit.tools/embed/en-US/download-time-calculator"
width="100%"
height="600"
style="border:0"
loading="lazy"
title="Download Time and Bitrate Calculator"
></iframe>These references help contextualize formulas, standards, APIs and limitations used on this page. They do not replace professional validation when a result has legal, financial, medical or operational impact.
At 100 Mbps, 80 seconds if the connection delivers its full speed; at 50 Mbps, 160 seconds; at 1 Gbps, 8 seconds. At 90% efficiency and 100 Mbps it would be about 89 seconds. In practice the origin server and Wi-Fi are usually the limit.
1 MB = 1,000,000 bytes, as on drives and most download pages. Mbps is always decimal.
ISPs sell speed in bits per second (Mbps). Files and browsers measure in bytes (MB). Since 1 byte is 8 bits, a download moves at one eighth of the advertised number: 100 Mbps delivers at most 12.5 MB/s.
Your speed: 100 Mbps equals 12.5 MB/s.
size in bits ÷ effective speed: 400,000,000,000 bit ÷ 100,000,000 bit/s = 4,000 s
Time to download each example, at 100% efficiency and the chosen byte base. Tap a name to calculate it.
| Example | 50 Mbps | 100 Mbps | 300 Mbps | 500 Mbps | 1 Gbps |
|---|---|---|---|---|---|
| 5 GB | 13 min 20 s | 6 min 40 s | 2 min 13 s | 1 min 20 s | 40 s |
| 8 GB | 21 min 20 s | 10 min 40 s | 3 min 33 s | 2 min 8 s | 1 min 4 s |
| 50 GB | 2 h 13 min 20 s | 1 h 6 min 40 s | 22 min 13 s | 13 min 20 s | 6 min 40 s |
| 60 GB | 2 h 40 min | 1 h 20 min | 26 min 40 s | 16 min | 8 min |
| 100 GB | 4 h 26 min 40 s | 2 h 13 min 20 s | 44 min 27 s | 26 min 40 s | 13 min 20 s |
| 1,000 GB | 1 d 20 h 26 min | 22 h 13 min 20 s | 7 h 24 min 27 s | 4 h 26 min 40 s | 2 h 13 min 20 s |
Sizes are round examples, not measurements: games, movies and ISO images vary a lot.
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