# Billing

FlexFS billing is an intentionally uncomplicated process whereby you pay only for the data you store in flexFS. The only variable that applies is your cost / GB-month rate `Rm`

.

## Statistics gathering

Summary statistics for each flexFS volume are reported to Paradigm4 at least hourly. From those, we may see:

`example-volume: Bh bytes @ 2024-01-01 01:00`

Where:

- Bh = number of bytes stored in flexFS that hour

## Hourly rate calculation

An effective hourly rate is calculated as follows:

`Rh = Rm / Hm`

Where:

- Rh = hourly rate
- Rm = monthly rate (contracted)
- Hm = hours in the billing month

## Hourly cost calculation

For each hour, the average reported size of the volume in bytes is converted to GB and multiplied by the hourly rate.

`Ch = (Bh / 1,073,741,824) * Rh`

Where:

- Ch = hourly cost
- 1 GB = 1 GiB = 1,073,741,824 bytes (standard practice in cloud storage calculations)
- Rh = hourly rate (calculated earlier)

## Monthly cost calculation

We simply add up the calculated hourly costs, `Ch`

, for the month to determine the total cost for the month.

## Quarterly invoicing

For most customers, we send quarterly invoices on Net 30 payment terms.