Check one-way and two-way reinforced concrete slab deflection and minimum thickness requirements for various boundary conditions under ACI 318 standards.
Formula and method
Concrete slab thickness bounds are derived from boundary continuity to guarantee deflection control without calculating complex structural load paths.
Spans and constraints set divisors: Simply supported (20), one end continuous (24), both ends (28), and cantilevers (10).
Divisor is modified relative to reinforcing steel grades yields.
Recommended specifications round values to standard dimensional forms.
Frequently asked questions
What span conditions are supported?
The calculator supports four boundary conditions: simply supported (span/20), one end continuous (span/24), both ends continuous (span/28), and cantilever (span/10).
How does steel grade affect the estimate?
The estimator applies the displayed modification factor to its assumptions. Confirm whether that method and material grade are suitable for the project before using the result.
Is this for one-way or two-way slabs?
This calculator is designed for one-way slabs where the long-span to short-span ratio exceeds 2.0. For two-way slabs, both span directions should be considered.
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Calculations are preliminary estimates for planning and education.
Verify results against project documents and applicable codes with a licensed Professional Engineer.
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