0.82HOURS49MINUTES23SECONDS
Time may vary with congestion, server load, Wi-Fi and storage speed.
TRANSFER TIME TOOL
Download time calculator
Estimate how long a file will take to download using its size, your sustained download speed and practical protocol efficiency.
Advanced options (protocols, overhead, parallel connections)
Efficiency accounts for TCP/TLS overhead, congestion, disk speed and remote-server limits. Use 85–95% for a typical stable transfer.
TIME BY FILE SIZE AT 300 Mbps, 90% EFFICIENCY
OTHER SCENARIOS FOR 100 GB (90% EFFICIENCY)
How to calculate download time
Transfer time in seconds = file size in decimal GB × 8,000 ÷ sustained download Mbps. For example, 10 GB at 100 Mbps takes 800 seconds, or 13 minutes 20 seconds, at constant full throughput.
These examples use decimal units: 1 GB = 1,000 MB and 1 MB = 1,000,000 bytes. A 10 GiB file is approximately 10.737 GB, so it takes about 7.4% longer than a decimal 10 GB file at the same rate. This calculator uses GB, not GiB.
| Sustained speed | Ideal MB/s | 10 GB, 100% efficiency | 10 GB, 90% scenario |
|---|---|---|---|
| 25 Mbps | 3.125 MB/s | 53 min 20 sec | 59 min 16 sec |
| 50 Mbps | 6.25 MB/s | 26 min 40 sec | 29 min 38 sec |
| 100 Mbps | 12.5 MB/s | 13 min 20 sec | 14 min 49 sec |
| 200 Mbps | 25 MB/s | 6 min 40 sec | 7 min 24 sec |
| 500 Mbps | 62.5 MB/s | 2 min 40 sec | 2 min 58 sec |
| 1000 Mbps | 125 MB/s | 1 min 20 sec | 1 min 29 sec |
Efficiency is an assumption, not a measurement
At 90% efficiency, 10 GB at 100 Mbps takes about 14 minutes 49 seconds. The percentage is a chosen scenario covering capacity unavailable to this transfer; it does not identify protocol overhead or congestion separately. If your input is already the sustained file-transfer rate, use 100% to avoid discounting it twice.
Estimate game downloads and large files
A decimal 100 GB game download at a sustained 200 Mbps takes 1 hour 6 minutes 40 seconds ideally. Server throttling, other transfers, Wi-Fi and storage can increase the duration. Installation, unpacking and patches are separate from the file transfer.
How long to download 100 GB at 100 Mbps?
A decimal 100 GB download at a sustained 100 Mbps takes 8,000 seconds: 2 hours 13 minutes 20 seconds ideally. At a chosen 90% efficiency it is about 2 hours 28 minutes 9 seconds. A game launcher may also install, verify or unpack files after downloading; this calculator estimates the transfer only.
For a game download time calculator by internet speed, enter the actual download size in GB and sustained Mbps. Storage requirements are not always the size transferred over the network.
Choose the next useful check
Follow the file-transfer calculation guide for a step-by-step example.
Measure download and upload throughput, then use the download time calculator, upload time calculator or Mbps to MB/s converter. If actual transfers remain slow, follow the slow-internet troubleshooting flow.
More Mbps reduces transfer time but does not change the speed of light in fiber. Compare fiber propagation delay per kilometre, calculate a route’s latency floor or read what 200 Mbps means for work and streaming.
Frequently asked questions
Does 100 Mbps mean 100 MB/s?
No. 100 Mbps equals 12.5 MB/s before overhead. A transfer rate of 100 MB/s requires 800 Mbps of payload throughput.
Can this calculator predict an exact finish time?
No. It assumes a constant sustained rate and the entered file size. Rate changes, remote-server limits and processing after transfer can change completion time.
Should I enter advertised or measured speed?
Use sustained speed for the relevant direction and destination when available. An advertised plan speed is a capacity scenario, not a measured transfer rate.