Concrete Crack Width Calculator

Estimate expected crack width based on reinforcement, concrete cover, and tensile strain

Common values: 12mm, 16mm, 20mm, 25mm
Center-to-center distance between bars
Distance from bar surface to concrete surface
Typical range: 0.0005 – 0.003
Depends on bond properties (0.8-1.4)
0.00
Crack Width (mm)
Expected maximum crack width

Interpretation of Results

Enter your values and click “Calculate” to see results.

Industry Standards Reference

  • ACI 224R-01: Recommended crack width limits: 0.33mm (exterior) to 0.41mm (interior)
  • Eurocode 2: Typical limit: 0.3mm for reinforced concrete under quasi-permanent loads
  • BS 8110: Suggests 0.3mm limit for normal environments

About This Calculator

This calculator estimates crack width in reinforced concrete members using the formula from Eurocode 2 (EN 1992-1-1). The calculation considers the bond properties between concrete and reinforcement, strain distribution, and geometric parameters.

Formula Used

wk = k × sr,max × εsm

Where:

  • wk = Crack width (mm)
  • k = Coefficient (depends on bond properties)
  • sr,max = Maximum crack spacing (mm)
  • εsm = Mean strain in reinforcement