Transfer details
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Free file transfer time estimator
Free Download Time Calculator
A download time calculator estimates how long a file transfer takes by converting the file size to bits and dividing by the connection speed in bits per second. Enter a size and speed to estimate any download or upload, with decimal and binary units and real-world efficiency.
Estimated transfer time
Estimated download time 13 minutes 20 seconds.
Estimated download time
13 minutes 20 seconds
At 100% efficiency. Ideal at full line rate: 13 minutes 20 seconds
Effective rate
100 Mbps
12.5 MB/s
Remaining data
10 GB
100% left
Total data
10 GB
10,000,000,000 bytes
Already downloaded
0 bytes
0%
Projected completion (Eastern Time)
Calculating...
If the transfer started now and held the effective rate. Shown in America/New_York.
Compare common speeds
| Speed | Ideal | At 100% |
|---|---|---|
| 10 Mbps | 2 hours 13 minutes | 2 hours 13 minutes |
| 25 Mbps | 53 minutes 20 seconds | 53 minutes 20 seconds |
| 50 Mbps | 26 minutes 40 seconds | 26 minutes 40 seconds |
| 100 Mbps | 13 minutes 20 seconds | 13 minutes 20 seconds |
| 300 Mbps | 4 minutes 27 seconds | 4 minutes 27 seconds |
| 500 Mbps | 2 minutes 40 seconds | 2 minutes 40 seconds |
| 1 Gbps | 1 minute 20 seconds | 1 minute 20 seconds |
| 2 Gbps | 40 seconds | 40 seconds |
| 10 Gbps | 8 seconds | 8 seconds |
Estimate only. This page does math on your inputs and does not test your connection or transfer any data. Real speeds vary with network conditions and server limits.
How download time is calculated
Transfer time depends on how many bits must move and how many bits per second the link actually delivers.
1. Convert size to bits
Multiply bytes by 8. 10 GB is 10,000,000,000 bytes, or 80,000,000,000 bits.
2. Convert speed to bits/s
100 Mbps is 100,000,000 bits per second. 100 MB/s is 800,000,000 bits per second.
3. Divide and adjust
Divide bits by bits per second, then divide by efficiency to allow for overhead.
time (s) = remaining bytes x 8 / (speed in bits/s x efficiency)
Units at a glance
File size
- KB
- kilobyte, 1,000 bytes
- MB
- megabyte, 1,000,000 bytes
- GB
- gigabyte, 10^9 bytes
- TB
- terabyte, 10^12 bytes
- KiB
- kibibyte, 1,024 bytes
- MiB
- mebibyte, 1,048,576 bytes
- GiB
- gibibyte, 2^30 bytes
- TiB
- tebibyte, 2^40 bytes
Connection speed
- Kbps
- kilobits per second, 1,000 bits/s
- Mbps
- megabits per second, 1,000,000 bits/s
- Gbps
- gigabits per second, 10^9 bits/s
- KB/s
- kilobytes per second, 8,000 bits/s
- MB/s
- megabytes per second, 8,000,000 bits/s
- GB/s
- gigabytes per second, 8 x 10^9 bits/s
Lowercase b means bits and uppercase B means bytes. Decimal prefixes (k, M, G, T) are powers of 1000; binary prefixes (Ki, Mi, Gi, Ti) are powers of 1024, as described in the NIST reference on prefixes for binary multiples.
Download time questions
How do I calculate download time?
Convert the file size to bits by multiplying bytes by 8, then divide by the connection speed in bits per second. For example, 10 GB is 80,000,000,000 bits, so at 100 Mbps (100,000,000 bits per second) it takes 800 seconds, or 13 minutes 20 seconds.
What is the difference between Mbps and MB/s?
Mbps means megabits per second and MB/s means megabytes per second. One byte is 8 bits, so 100 Mbps equals 12.5 MB/s. Internet plans are usually sold in Mbps, while many download managers show MB/s.
What is the difference between GB and GiB?
GB is a decimal unit equal to 1,000,000,000 bytes. GiB is a binary unit equal to 1,073,741,824 bytes (1024^3), as defined by the IEC prefixes described by NIST. Some operating systems label GiB values as GB, so a file may look smaller than its decimal size.
Why is my real download slower than the estimate?
Protocol overhead, Wi-Fi signal, network congestion, VPNs, and server-side limits all reduce real throughput. Set efficiency to 80% or 90% for a more conservative estimate, or measure your connection first with a speed test.
Does this calculator test my connection or download anything?
No. It only does math on the numbers you enter, entirely in your browser. It does not measure your connection, transfer files, or store your inputs.
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