> ## Documentation Index
> Fetch the complete documentation index at: https://calcs.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

> Engineering reference articles supporting Calcs.com calculators

Background engineering concepts referenced across Calcs.com calculators, useful when interpreting results or setting up complex designs.

<CardGroup cols={2}>
  <Card title="Footings Under Biaxial Bending" icon="square" href="/docs/engineering-concepts/footings-under-biaxial-bending">
    Eccentric bearing, moment effects, and footing design context
  </Card>

  <Card title="Eurocodes & National Annexes" icon="globe" href="/docs/engineering-concepts/eurocodes-national-annexes-where-to-get-them">
    Where to find Eurocode documents and national annexes
  </Card>
</CardGroup>

## Related guides

<CardGroup cols={2}>
  <Card title="US Spread Footings" icon="flag" href="/docs/calculators/foundations-and-retaining-walls/us/how-to-design-spread-footing">
    Design spread footings to ACI 318-14
  </Card>

  <Card title="Europe Calculators" icon="world" href="/docs/calculators/library/eu">
    Eurocode-based design calculators
  </Card>
</CardGroup>