File Transfer CalculatorPrivacy: All calculations run locally
Calculate transfer time, required speed, or transferable file size for downloads, uploads, network copies, disk copies, backups and archive operations.
Scenario
Enter numbers using a period or comma as the decimal separator — no thousands separator, no scientific notation.
Inputs
Advanced: Efficiency
How It Works
Pick a scenario to get sensible default units and labels, then choose what you want to calculate: Transfer Time (from a size and a rate), Required Speed (from a size and a target time), or Transferable Size (from a rate and an available time). Values you enter for file size, transfer rate and duration are shared across modes, so switching tabs never loses what you typed.
Decimal vs. binary units. Decimal units (KB, MB, GB, TB — powers of 1000) are how storage and network speeds are usually advertised. Binary units (KiB, MiB, GiB, TiB — powers of 1024) are how operating systems often report file and disk sizes. 1 GB and 1 GiB are different quantities (1,000,000,000 bytes vs. 1,073,741,824 bytes) — this tool never mixes them up silently.
Efficiency models the gap between a nominal, advertised rate and the throughput you actually get in practice, due to protocol overhead, retransmissions and shared traffic. At 100% efficiency, the full entered rate is treated as useful throughput. Lower values increase the required nominal rate, the estimated time, or reduce the transferable size accordingly.
All results are estimates. Real-world transfers are also affected by latency, disk I/O, other running processes and hardware limits that this calculator does not model — especially for the Extract Archive and Compress Files scenarios, where throughput mostly depends on CPU speed rather than network or raw disk transfer rate.