# Writing custom calculations

With Tedds for Word, you can either perform pre-defined structural calculations, or write and use your own calculations. This section introduces the basic Tedds for Word calculations and their components.

Using
Tedds for Word, you can:

- Define and perform your own calculations in any Microsoft Word document quickly and simply.
- Access standard calculations by using the Library Access System.
- Access component calculations by using the Library Access System.
- Include engineering data in your calculations by using data lists, data tables, and data graphs.
- Calculate anything from a single calculation to an entire document.
- Automatically verify the dimensional accuracy of your calculations by specifying the appropriate units for your variables.
- Define multiple calc sections in your document, so that the same variables can have different values within your document.