MbpsToGbps
Real-world overhead

About 85% of the advertised rate, which is what a healthy wired connection tends to deliver.

In GB - leave at 1000 for a 1 TB cap

Data transferred

38.25GB

100 Mbps x 1 hour at 85% efficiency

In gigabytes

38.25 GB

Decimal GB, as ISPs count it

In gigabits

306.00 Gb

The same data in bits

4K movies

1.5

At 25 GB each

1,000 GB cap lasts

1 d 2 h 8 min

At this rate, non-stop

Data moved at 100 Mbps over different windows.
WindowDataIn GB
1 minute637.50 MB0.64 GB
1 hour38.25 GB38.25 GB
8 hours306.00 GB306.00 GB
1 day918.00 GB918.00 GB
1 week6.43 TB6,426.00 GB
30 days27.54 TB27,540.00 GB

Caps count bytes, not bits

A data allowance is quoted in gigabytes while your line is sold in megabits per second. Dividing by eight is what connects the two: a 100 Mbps line running flat out moves about 10.6 MB every second, which is more than 3 TB in a month.