Estimate how long an initial cloud backup seed takes at your upload speed before incrementals take over.
Gigabytes are converted to megabits by multiplying by 8,000, then divided by the throughput actually achieved. Real transfers never hit line rate because of protocol overhead, disk speed and contention, so the efficiency factor derates it first. A backup seed quoted at line rate is always optimistic; planning a maintenance window on the derated figure is what stops it overrunning.
Online Backup Time
Time = size × 8,000 ÷ (line rate × efficiency), in seconds
Time = size × 8,000 ÷ (line rate × efficiency), in seconds Gigabytes are converted to megabits by multiplying by 8,000, then divided by the throughput actually achieved. Real transfers never hit line rate because of protocol overhead, disk speed and contention, so the efficiency factor derates it first.
A backup seed quoted at line rate is always optimistic; planning a maintenance window on the derated figure is what stops it overrunning.
This calculator takes 3 inputs: Initial backup size, Connection speed, Achieved share of line rate. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.