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RCC Footing Steel Calculator (Isolated, Strip & Circular — Main Bars, Distribution Bars, Steel Weight & Procurement)

Calculate RCC footing reinforcement, steel weight, wastage, and stock bar procurement.

Inputs

Footing Dimensions

ℹ️Isolated/Pad supports a single column. Strip/Continuous runs under a wall or a closely spaced row of columns — same mesh formula as Isolated, just with the primary reinforcement direction swapped. Circular/Pier is a round base, reinforced here as a simplified mesh sized to the diameter.

ℹ️Length of footing in the longer direction. Allowed range: 500-5000 mm.

ℹ️Width of footing in the shorter direction. Allowed range: 500-5000 mm.

ℹ️Overall footing thickness. Allowed range: 150-1500 mm.

ℹ️Enter the number of identical footings. All footings are calculated using the same dimensions and reinforcement.

Bottom Main Bars

Bottom Distribution Bars

Optional Top Mesh

ℹ️Required for large footings, combined footings, raft foundations, uplift conditions, or drawings specifying top reinforcement.

Cover and Procurement

ℹ️IS 456: 50 mm with PCC blinding, 75 mm without PCC blinding. Use 100 mm for aggressive soil or chemical exposure.

ℹ️Used when footing dimensions exceed stock bar length.

Net Footing Steel

49.33 kg

Bottom steel: 49.33 kg

Top steel: 0 kg

Total length: 65.4 m

Concrete volume: 1.89

Recommended Procurement

51.8 kg

Wastage (5%): 2.47 kg

Footings: 2

Stock bar length: 12 m

Steel consumption: 26.1 kg/m³

Weight Contribution

Bottom Main bars29.33 kg
Bottom Distribution bars20 kg
Net Steel49.33 kg

Footing Steel Breakdown

Bar TypeDiaSpacingQtyCutting LengthTotal LengthWeight
Bottom Main bars12 mm150 mm201.65 m33 m29.33 kg
Bottom Distribution bars10 mm150 mm241.35 m32.4 m20 kg
TOTAL----65.4 m49.33 kg

Compliance Checks

Cover: PASS (75 mm)

Spacing: PASS

Minimum steel: Adequate

Minimum Reinforcement

Required: 420 mm²/m

Main provided: 753.98 mm²/m (180% of minimum requirement)

Distribution provided: 523.6 mm²/m (125% of minimum requirement)

Steel consumption: 26.1 kg/m³49.33 ÷ 1.89 = 26.1 kg/m³

Equivalent Stock Bars by Diameter

10 mm: 3 bars (21 kg)

12 mm: 3 bars (30.8 kg)

Approximate results for planning only. Verify with a professional.

Footing Steel Mesh LayoutIndicative bottom reinforcement mesh — bar count simplified for clarity1800 x 1500 mm350 mm thick12 mm main bars10 mm distribution bars

Looking for the verification checklist, reference tables, tips, or common mistakes?See the complete Footing Steel Calculator.

RCC footing reinforcement estimate

This page is set up for two rectangular isolated footings.

This calculator page is pre-filled for the selected footing case. Edit any input and the worked example updates from the active values.

  • Default footing: 1.8 m x 1.5 m.
  • Two footings included.
  • 75 mm cover.

How does the footing steel calculator work?

Footing steel quantity is calculated for two orthogonal bar groups — one spaced across the width and running the full effective length, the other spaced across the length and running the full effective width — plus optional top mesh. Isolated and Strip footings use this exact same formula; only which group is the primary ("main") reinforcement swaps, since a Strip footing's dominant bending direction is transverse, not longitudinal. Circular footings use the same two-group formula sized to the effective diameter in both directions — a simplified mesh, not a radial/ring layout (see Limitations).

Step 1 — Calculate Effective Footing Dimensions

Isolated/Strip: Effective Length = Length − (2 × Cover), Effective Width = Width − (2 × Cover)

Circular: Effective Diameter = Diameter − (2 × Cover), used as both dimensions

Concrete cover is deducted because reinforcement must remain inside the concrete cover zone.

Step 2 — Calculate Bar Group Counts

Group A (Main/Longitudinal) Count = ceil(Effective Width ÷ Group A Spacing) + 1

Group B (Distribution/Transverse) Count = ceil(Effective Length ÷ Group B Spacing) + 1

Group A runs along the length and is counted across the width. Group B runs along the width and is counted across the length. For Circular, both use the effective diameter, so the mesh is symmetric.

Step 3 — Calculate Cutting Lengths

Group A Cutting Length = Effective Length

Group B Cutting Length = Effective Width

For simple mesh estimation, straight bar cutting length is taken as the effective dimension after cover deduction.

Step 4 — Check Lap Length if Required

Lap Length = Bar Diameter × Lap Multiplier

If Cutting Length > Stock Bar Length, Adjusted Cutting Length = Cutting Length + Lap Length

Lap length is added only when a bar length exceeds the available stock bar length — common for Strip footings' long longitudinal bars.

Step 5 — Calculate Steel Weight

Unit Weight = D² ÷ 162 kg/m

Total Bar Length = Cutting Length × Number of Bars × Number of Footings

Steel Weight = Total Bar Length × Unit Weight

Each bar group is converted from total length to weight using the standard steel unit weight formula.

Step 6 — Add Optional Top Mesh

Top Mesh Weight = Top Group A Weight + Top Group B Weight

Net Steel = Bottom Mesh + Top Mesh

Top mesh is included only when selected. It is commonly required for large footings, raft/combined footings, or uplift conditions.

Step 7 — Calculate Concrete Volume

Isolated/Strip: Volume = Length × Width × Thickness × Count

Circular: Volume = π × (Diameter / 2)² × Thickness × Count

Used to report steel consumption in kg per cubic metre of footing concrete.

Step 8 — Calculate Wastage and Procurement

Wastage = Net Steel × Wastage %

Total to Procure = Net Steel + Wastage

Stock Bars Required = Total Bar Length ÷ Stock Bar Length, rounded up

Final procurement quantity includes wastage and converts steel length into equivalent stock bar counts.

This calculator estimates footing mesh steel quantity for procurement planning only. Final footing reinforcement, bar direction, development length, dowels, pedestal bars, punching shear reinforcement, and top mesh requirements must follow approved structural drawings.

Worked Example

This example uses the active inputs above and follows the same steps as the Formula section.

Input Values Used

InputValue
Footing TypeIsolated / Pad Footing
Length1800 mm
Width1500 mm
Thickness350 mm
Cover75 mm
Count2
Top MeshNot included
Wastage5%

Step 1 — Effective Dimensions

Effective Length = 1.65 m, Effective Width = 1.35 m

Step 2 — Bar Groups & Weight

Bar TypeCountCutting LengthTotal LengthWeight
Bottom Main bars (12 mm @ 150 mm)201.65 m33 m29.33 kg
Bottom Distribution bars (10 mm @ 150 mm)241.35 m32.4 m20 kg
Bottom Steel49.33 kg
Top mesh is not included for this example, so top steel weight is 0 kg. Confirm the structural drawing before excluding top reinforcement.

Step 4 — Net Steel, Wastage & Procurement

ComponentQuantity
Net Steel49.33 kg
Wastage (5%)2.47 kg
Total to Procure51.8 kg
Concrete Volume1.89
Steel Consumption26.1 kg/m³

Therefore, for 2 isolated / pad footing(s) the estimated footing mesh steel is 49.33 kg net and 51.8 kg for procurement including 5% wastage.

Cross-check against the Quick Reference Tables in the complete Footing Steel Calculator.

FAQ

This page is pre-filled for RCC footing steel calculator so you can estimate footing main bars, distribution bars, optional top mesh, steel weight, wastage, and approximate stock bar procurement.
Yes. You can edit footing type, dimensions, number of footings, bar diameters, spacing, top mesh, cover, stock bar length, lap multiplier, and wastage allowance.