A 10 GB file on a 100 Mbps connection
10 GB is 80 billion bits. At a steady 100 Mbps, the ideal transfer takes 800 seconds, or 13 minutes 20 seconds. With 90% usable speed and no startup delay, the estimate rounds up to 14 minutes 49 seconds.
File and connection
Internet plans usually use Mbps (megabits per second). Download apps often show MB/s (megabytes per second). One byte is 8 bits.
90% is an example allowance, not a measured prediction. Use 100% with an observed app transfer rate to avoid counting overhead twice.
Estimated remaining time
At 90% usable speed
14 minutes, 49 seconds
11.25 MB/s effective transfer rate
| Breakdown | Value |
|---|---|
| Total file size | 10,000,000,000 bytes |
| Remaining data | 10,000 MB |
| Ideal remaining transfer at 100% | 13 minutes, 20 seconds |
| Transfer at chosen usable speed | 14 minutes, 49 seconds |
| Additional startup delay | 0 seconds |
Time = remaining bytes × 8 ÷ usable bits per second, plus startup delay. Whole-second durations round up. A finished or empty file needs no transfer or startup time.
If your speed changes
| Connection speed | Remaining estimate |
|---|---|
| 50 Mbps | 29 minutes, 38 seconds |
| 100 Mbps | 14 minutes, 49 seconds |
| 200 Mbps | 7 minutes, 25 seconds |
This calculator does not run a speed test. Wi-Fi, server limits, competing traffic, retries, and changing connection rates can affect actual transfer time. For uploads, use your upload speed.
All estimates run in your browser. No connection test or file upload is performed.
How to use the Download Time Calculator
- 01
Enter the total file size and its unit. Use GB for decimal gigabytes or GiB for binary gibibytes.
- 02
Enter the connection or observed transfer speed, checking whether the unit uses bits or bytes.
- 03
Set usable speed, completed percentage, and any remaining startup delay. Read or copy the remaining-time estimate.
Examples
A measured app speed in MB/s
A 500 MB file at 10 MB/s takes 50 seconds at 100% usable speed. That speed is 80 Mbps. Use 100% when your observed transfer rate already reflects network overhead.
Resume a partly completed transfer
If a 4 GiB file is 25% complete, 3 GiB remain. At 20 MiB/s and 100% usable speed, the remaining data takes 153.6 seconds, displayed as 2 minutes 34 seconds. Add a known startup delay separately.
Bits, bytes, and the factor of eight
One byte contains 8 bits. Mbps means millions of bits per second; MB/s means millions of bytes per second. A connection running at 80 Mbps has an ideal data rate of 10 MB/s. Match the unit shown by your internet plan or download app before calculating.
Decimal and binary file sizes
This tool uses decimal prefixes for KB, MB, GB, and TB: each step is a factor of 1,000. Binary KiB, MiB, GiB, and TiB use a factor of 1,024 per step. For example, 1 GB is 1,000,000,000 bytes and 1 GiB is 1,073,741,824 bytes. Some apps label binary values with decimal-looking abbreviations; check the app’s convention if an estimate seems off.
How the estimate works
Remaining bytes equal total bytes multiplied by the unfinished fraction. Effective speed equals the entered speed multiplied by the usable-speed percentage. Transfer seconds equal remaining bytes × 8 ÷ effective bits per second. Startup delay is added once, and whole-second durations round up. Empty files and transfers marked 100% complete return zero remaining time.
Choose a realistic usable-speed setting
The default 90% is an editable example allowance, not a measurement or universal overhead rate. A nominal service speed may differ from a sustained transfer rate because of Wi-Fi, server limits, shared traffic, and retransmissions. If you already have a stable observed MB/s value from the app, entering that with 100% usable speed usually avoids applying an allowance twice.
What to know
- Assumes a steady average transfer rate. It does not measure a connection, server performance, or future congestion.
- Usable speed must be greater than 0% and at most 100%. Startup delay is limited to one day.
Common questions
Can I calculate upload time too?
Yes. Use your upload speed. Upload and download rates can differ substantially, even on the same internet plan.
Does this calculator test my connection?
No. It calculates from the numbers you provide and makes no network speed measurement.
Should I enter the whole file or only the remaining size?
Either works if you avoid counting progress twice. Enter the whole file and the completed percentage, or enter only the remaining size with 0% completed.
Does the estimate include installation or decompression?
No. The calculator covers data transfer plus the explicit startup delay you enter. Installation, decompression, scanning, and other processing need separate time estimates.