Slab Calculator
Estimate concrete volume, steel weight and bending moment for an RCC slab.
Estimates only — not professional financial, medical, legal or engineering advice. Read full disclaimer.
Calculating...
Result
Fill in the form and click Calculate to see your result here.
How it's calculated
Concrete Volume = Length × Width × Thickness. Steel Weight = Concrete Volume × Steel % × 7850 kg/m³. Max Bending Moment = (UDL × Shorter Span²) ÷ 8.
Example
Example: Slab Calculator
Inputs
- Length: 5
- Width: 4
- Thickness: 150
- Steel Percent: 0.8
- Udl: 5
Outputs
- Concrete Volume: 3
- Steel Weight: 188.4
- Max Bending Moment: 10
This example uses typical sample values. Adjust the inputs above to see how the results change for your own numbers.
About this calculator
The Slab Calculator estimates the concrete volume and reinforcement steel weight for a reinforced concrete slab based on its dimensions and a typical steel reinforcement percentage, and also reports the maximum one-way bending moment under a design load.
Frequently Asked Questions
0.7% to 1% of the concrete volume is a common range for slab reinforcement, though the exact figure depends on the structural design and span - the calculator defaults to 0.8%.
The calculator multiplies concrete volume by the steel percentage to get steel volume, then multiplies by steel's density (7850 kg/m³) to get weight - a quick estimate, not a substitute for detailed rebar design.
It uses the shorter of the slab's length and width, consistent with one-way slab design where the shorter span typically governs the main reinforcement direction.
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