Per-unit pricing model
The per-unit pricing model is one of the pricing models. This page explains how it calculates the amount of a pricing preset.Map of concepts
Related modules
The following modules use the per-unit pricing model:Per-unit pricing model: the same price for every unit
The per-unit pricing model is the pricing model that charges the same price for every unit. The per-unit pricing model has one value: the price per unit, in Price per unit. For each period, the amount is the quantity of that period multiplied by the price per unit:
Zenskar keeps the full precision of the price per unit during the calculation. It rounds the amount to the currency at the end of the calculation of the line item.
What a period is depends on the product type. See Point-in-time products and Period-of-time products.
Point-in-time products: one charge for each unit
For a point-in-time product, the price per unit is the price of one unit, with no period attached. For example, $0.01 per SMS. A pricing preset of a point-in-time product has no pricing period. Zenskar charges each unit once, in the billing period in which the line item counts it. The amount of each billing period is the quantity of that billing period multiplied by the price per unit. Billing periods do not affect each other: the price per unit stays the same, however many units earlier billing periods had. A pricing preset at $0.01 per SMS, with metered usage and monthly billing, gives the following amounts:
The line item decides which units fall in which billing period, through its quantity strategy and its billing. See Line item: quantity and Line item: billing.
Period-of-time products: a price for each pricing period
For a period-of-time product, the price per unit covers one pricing period. For example, $20 per seat per month. Every pricing preset of a period-of-time product has a pricing period, and the pricing period is monthly by default. The billing periods of a line item do not have to match the pricing period. Zenskar converts the price to the length of each billing period with the period ratio. The period ratio is the length of a billing period divided by the length of its pricing period. For each billing period, the amount is:
The period ratio counts calendar months, not days. A monthly billing period of a quarterly price has a period ratio of 1/3 in February and in March alike, so both months cost the same. A pricing period is always a whole number of months or years.
The pricing period and the billing period must align: one must be a whole multiple of the other. See Line item: billing.
This section describes billing periods that the line item covers in full, with the recurring quantity strategy. For billing periods that the line item covers only in part, see Partial periods. For the on-demand quantity strategy, see On-demand quantities.
Partial periods
A billing period is partial when the line item covers only some of its days. For example, a line item that starts on February 15, 2024, with monthly billing periods that start on the 1st of each month, covers 15 of the 29 days of February. The anchor date of the line item decides the day on which billing periods start. A billing period also splits into parts when the quantity changes partway through it. For example, 10 seats from March 1 to March 15 and 25 seats from March 16 to March 31. For a period-of-time product with the recurring quantity strategy, the partial-period handling of the line item decides the amount of each partial part:
A pricing preset at $29 per seat per month, with 10 seats, monthly billing periods that start on the 1st, and a line item that starts on February 15, 2024, gives the following amounts for February:
A pricing preset at $30 per seat per month, with 10 seats from March 1 to March 15, 2024, and 25 seats from March 16 to March 31, gives the following amounts for March:
With Charge Full, each part of the billing period costs the amount of a full billing period. A quantity change partway through a billing period therefore charges that billing period more than once.
For a point-in-time product, the pricing model does not prorate. Each unit costs the full price per unit. The line item can prorate a recurring fixed quantity before the pricing model calculates. See Line item: quantity.
The on-demand quantity strategy never prorates. See On-demand quantities.