# Beams: the minimum area of longitudinal reinforcement following the EN Eurocode recommendation, `A`_{s,min}

_{s,min}

## Eurocode 2 part 1-1: Design of concrete structures 9.2.1.1 (1)

The recommended value for the minimum reinforcement areas is:

A = 0,26 (_{s,min}f / _{ctm}f) _{yk}b _{t}d ≥ 0,0013 b _{t}d | (9.1N) |

where:

`f`_{ctm}- is the mean value of axial tensile strength of concrete at 28 days, see Table 3.1
`f`_{yk}- is the characteristic yield stress of reinforcement steel
`b`_{t}- is the mean width of the tension zone; for a T-beam with the flange in compression, only the width of the web is taken into account in calculating the value of
`b`_{t} `d`- is the effective depth of concrete cross-section.

This application calculates
the minimum area of reinforcement `A _{s,min}`
from your inputs.