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StorageMath

Data Transfer Time Calculator

Need to know how long a migration or backup will take at your actual link speed? Enter the Data Size and its unit (GB, TB, or PB), your Transfer Speed, Speed Unit (Mbps, Gbps, MB/s, or GB/s), and the Efficiency Factor — the percentage of rated speed your link actually sustains — into the Data Transfer Time Calculator and click Calculate Transfer Time to get your estimated wall-clock duration.

File Size, Network Speed and Protocol: Enter Transfer Details

Calculated Transfer Duration at Your Speed and File Size

Total Transfer Time

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Days

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Hours

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Minutes

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Seconds

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Theoretical Speed

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Effective Speed

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USB 3.0, Gigabit Ethernet, Wi-Fi and Cloud Upload Time Examples

Estimated transfer times for common data sizes at 1, 10, 25 and 100 Gbps link speeds (at 80% efficiency)
Data Size 1 Gbps 10 Gbps 25 Gbps 100 Gbps
100 GB ~14 min ~1.4 min ~34 sec ~8 sec
1 TB ~2.4 hrs ~14 min ~5.7 min ~1.4 min
10 TB ~24 hrs ~2.4 hrs ~57 min ~14 min
100 TB ~10 days ~24 hrs ~9.5 hrs ~2.4 hrs
1 PB ~100 days ~10 days ~4 days ~24 hrs

* Times shown at 80% efficiency. Actual times may vary.

Why Advertised Mbps Speeds Differ from Actual File Transfer Rates

Understanding data transfer times is essential for planning successful migrations, backups, and disaster recovery operations. The theoretical transfer speed rarely matches real-world performance due to protocol overhead, network congestion, and storage system limitations. This calculator helps you estimate realistic transfer durations. Related: Storage capacity planning tool.

When planning a data migration, always factor in efficiency losses. A typical enterprise network achieves 70-80% of theoretical bandwidth, while WAN connections may see even lower utilization. Protocol overhead from TCP/IP, storage protocols like iSCSI or FC, and file system metadata all contribute to reduced effective throughput. Check out our calculate storage IOPS performance.

For large-scale migrations exceeding 100TB, consider breaking the transfer into smaller batches and scheduling during off-peak hours. This approach reduces impact on production systems and provides checkpoints for verification. Always validate data integrity after transfer completion using checksums or comparison tools. See also: StorageMath calculators.

Overhead, Compression, Protocol and Drive Speed Impact on Transfer Time

  • LAN transfers (90-95%): Direct connections with minimal overhead
  • Enterprise networks (70-85%): Typical datacenter with some congestion
  • WAN/Internet (50-70%): Long-distance transfers with higher latency
  • Cloud uploads (40-60%): Variable based on provider and location