Download Time Calculator
Calculate how long a file will take to download at a given connection speed.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
File sizes use decimal units: 1 GB = 1,000 MB and 1 TB = 1,000,000 MB. Connection speed is decimal Mbps; divide by eight to convert megabits to megabytes, then account for the overhead entered. Actual speeds vary.
Worked example
calculated with the default values below
File size 5 GB · File size unit Gigabytes · Connection speed 100 Mbps · Protocol overhead 8 % · Number of files 1 Download time 7 min 15 s · Download time 434.8 s · Total data (decimal MB) 5,000.0 MB · Effective speed 92.00 Mbps · Effective speed 11.50 MB/s
General background references
Disclaimer
These calculators give general date results. Public holidays, working-day conventions and time-zone rules are set locally and change, so confirm against the official calendar for anything legally or contractually binding.
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
t = S × u × n × 8 ÷ (V × (1 − o ÷ 100))
- S
- file size
- u
- decimal unit factor to MB
- n
- number of files
- V
- connection speed, Mbps
- o
- overhead, %
- t
- download time, seconds
Decimal units: GB=1,000 MB, MB=1, TB=1,000,000 MB, kb=1/8,000 MB. Speed is decimal Mbps; ×8 converts MB to megabits.
Frequently asked questions
What should I know about this estimate?
File sizes use decimal units: 1 GB = 1,000 MB and 1 TB = 1,000,000 MB. Connection speed is decimal Mbps; divide by eight to convert megabits to megabytes, then account for the overhead entered. Actual speeds vary.