# Various Rule: Per Day

The Per Day rule uses the entered rate and the calculated number of days to estimate the various amount.

$$
Amount = Days \times Rate
$$

Days are calculated differently depending on the entity the various item is created for.

* For **voyage**, the voyage duration is used: the difference between the voyage start date and the last port call’s departure date, and the estimated days are stored in the various item’s quantity
* For **cargo**, the voyage duration is also used
* For **downtime**, the offhire duration is used
* For **port call**, the duration between the arrival and departure dates is used.

***

{% hint style="warning" %}

### Important notes about the Per Day rule

* The various amount for each item is **updated** dynamically as the **voyage, downtime** or **port call** days change.
  {% endhint %}