Internet Speed Calculator
Convert between Mbps, MB/s and download times, and check what a speed can actually support.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
Download time converts Mbps to MB/s and includes the overhead you enter. Per-device speed assumes an even split, which real networks do not guarantee. The streaming counts are rough capacity estimates; provider requirements, Wi-Fi and other traffic affect actual results. Latency is shown as a measurement, not a gaming verdict.
Worked example
calculated with the default values below
Connection speed 200 Mbps · File size 10 GB (decimal) · Simultaneous heavy devices 4 · Protocol overhead 8 % Estimated download time 7.2 min · Speed in megabytes per second 23.00 MB/s · Bandwidth per device 46.0 Mbps · Simultaneous 4K streams possible 7.0 · Simultaneous HD streams possible 36.0
General background references
Disclaimer
These calculators give general estimates. Sizing, pricing, availability and standards vary by brand, retailer and country, so treat the output as a starting point and confirm it against the seller's or authority's own figures.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
download minutes = file size (decimal GB) × 1,000 × 8 ÷ effective Mbps ÷ 60
- v
- Effective throughput (Mbps)
- S
- Nominal connection speed (Mbps)
- o
- Protocol overhead (%)
- t
- Download time (seconds)
- F
- File size (GB)
Per-device throughput assumes an even split; stream counts use rough planning thresholds. Latency is reported without a universal gaming verdict.
Frequently asked questions
Why is per-device speed only an estimate?
It divides effective bandwidth evenly among devices. Real devices do not share bandwidth equally, and Wi-Fi quality, congestion and service conditions can change speeds.