Concrete beam analysis.

Enter a rectangular section to explore its bending resistance. Change an input to recalculate the result.

Section result

Singly reinforced

Flexural resistance— kNm

—

Neutral axis, x—

Relative depth, x/d—

Steel strain, εₛ—

Steel stress, σₛ—

Calculation steps

Force equilibrium—
Concrete compression, C_c = 0.8 f_cd b x—
Top steel contribution, C_s′—
Moment about tension steel, M_Rd—

Educational section analysis using plane sections, ε_cu = 3.5‰, E_s = 200 GPa and a rectangular concrete block of depth 0.8x at f_cd. Steel stress follows compatible strain, capped at ±f_yd. This checks flexure only; it does not check shear, detailing, minimum or maximum reinforcement, serviceability or the current national annex. See JRC worked examples ↗

Concrete beam analysis.

Section geometry

Design strengths & action

Section result