Crack Width Calculator

Calculate crack widths in reinforced concrete beams and slabs per ACI 318 requirements.

Section Parameters

in
in
ksi

Service load stress in reinforcement (typically 0.6fy)

in
in

Calculated Crack Width

7.15 mils

0.18 mm | Allowable: 16.00 mils

Utilization
44.7%
Beta Factor
1.140
Max Spacing
20.0"
dc
2.31"

Crack Width: OK

w = 7.15 mils vs w_allow = 16.00 mils

Bar Spacing: OK

s = 6" vs s_max = 20.0"

Crack Width Limits:

Interior Exposure16 mils (0.4 mm)
Exterior Exposure13 mils (0.3 mm)
Severe Exposure10 mils (0.25 mm)