Download Time Calculator
How long a file takes at your connection speed.
Enter your values
Enter the file size in GB.
Enter the connection speed in Mbps.
Enter the real-world efficiency in %.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Download time
- 8m 1s
- Effective speed
- 80 Mbps (10 MB/s)
- Total data
- 4813 MB
- Time at full advertised speed
- 6.4 minutes
Quick answer
Download time is file size in bits divided by connection speed in bits per second; remember 1 byte is 8 bits.
Time = size (MB) × 8 ÷ speed (Mbps)
At a glance
| What it does | How long a file takes at your connection speed. |
|---|---|
| Category | Conversions |
| Inputs needed | File size, Connection speed, Real-world efficiency |
| Main output | Download time |
| Formula | Time = size (MB) × 8 ÷ speed (Mbps) |
| Cost | Free — no sign-up, no download |
How to use the Download Time Calculator
- 1Enter the file size in gigabytes.
- 2Enter your connection speed in Mbps.
- 3Adjust efficiency for real-world overhead.
Inputs explained
- File size(GB)
- Enter the file size in GB.
- Connection speed(Mbps)
- Enter the connection speed in Mbps.
- Real-world efficiency(%)
- Enter the real-world efficiency in %.
Worked example
Using the values the calculator loads with:
Inputs
- File size4.7 GB
- Connection speed100 Mbps
- Real-world efficiency80 %
Results
- Download time8m 1s
- Effective speed80 Mbps (10 MB/s)
- Total data4813 MB
- Time at full advertised speed6.4 minutes
Frequently asked questions
Why is my download slower than advertised?
Protocol overhead, server limits, Wi-Fi loss and congestion typically leave 70–85% of the headline speed.
Mbps vs MB/s?
Divide Mbps by 8 to get MB/s. A 100 Mbps line downloads at about 12.5 MB/s at best.
What do I need to enter into the Download Time Calculator?
Just 3 values: file size, connection speed, real-world efficiency. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Download Time Calculator work out the answer?
Download time is file size in bits divided by connection speed in bits per second; remember 1 byte is 8 bits. It applies the formula Time = size (MB) × 8 ÷ speed (Mbps) and shows the working so you can check each step by hand.
Is the Download Time Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.