> For the complete documentation index, see [llms.txt](https://brenkel-solutions-eg.gitbook.io/demandplus+/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://brenkel-solutions-eg.gitbook.io/demandplus+/english/pre-calculation/calculation.md).

# Calculation

The calculation is the heart of the complete module. Its where boms and routings will be exploded, aswell as costs for later evalatution calculated.

## Calculate item

If you want to recalculate a calculation, you can do this by clicking the “Calculate Item button.

![Figure 1: Calculate item](https://2996561529-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F9FjnF8aY9Sbfu95hrLfD%2Fuploads%2Fn4f8xOGX24hWsEw85uBQ%2F002_Kalkulation.png?alt=media\&token=881a7230-419e-4aef-ba61-8f15b08db714)

This will delete the lines and recalculate them again

## Prepare Calculation

U can prepare the calculation to apply your own schemes to the calculation.

![Figure 2: Prepare calculation](https://2996561529-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F9FjnF8aY9Sbfu95hrLfD%2Fuploads%2FJu5gXLeKUjsPtmQXksnx%2F003_Kalkulation.png?alt=media\&token=ce64d42d-f954-4025-a19c-93487b8f02db)

This will create a new schema for the calculation. For more information: [Schemas](/demandplus+/english/pre-calculation/schemas.md)