TryBuildCalcFooting Reinforcement Calculator (Isolated, Strip & Circular — Main Bars, Distribution Bars, Steel Weight & Procurement)
Calculate footing reinforcement from footing size, bar diameter, bar spacing, cover, top mesh, lap allowance, and wastage. Adjust footing type, size, bar spacing, top mesh, cover, stock bar length, lap allowance, and wastage for your footing reinforcement estimate.
Calculate RCC footing reinforcement, steel weight, wastage, and stock bar procurement.
🕒 Last updated: August 4, 2026
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
88.18 kg
Bottom steel: 55.61 kg
Top steel: 32.57 kg
Total length: 81.95 m
Concrete volume: 1.62 m³
Recommended Procurement
94.35 kg
Wastage (7%): 6.17 kg
Footings: 1
Stock bar length: 12 m
Steel consumption: 54.4 kg/m³
Weight Contribution
Footing Steel Breakdown
| Bar Type | Dia | Spacing | Qty | Cutting Length | Total Length | Weight |
|---|---|---|---|---|---|---|
| Bottom Main bars | 16 mm | 150 mm | 12 | 1.85 m | 22.2 m | 35.08 kg |
| Bottom Distribution bars | 12 mm | 150 mm | 14 | 1.65 m | 23.1 m | 20.53 kg |
| Top Main bars | 12 mm | 200 mm | 10 | 1.85 m | 18.5 m | 16.44 kg |
| Top Distribution bars | 12 mm | 200 mm | 11 | 1.65 m | 18.15 m | 16.13 kg |
| TOTAL | - | - | - | - | 81.95 m | 88.18 kg |
Compliance Checks
Cover: PASS (75 mm)
Spacing: PASS
Minimum steel: Adequate
Minimum Reinforcement
Required: 540 mm²/m
Main provided: 1,340.41 mm²/m (248% of minimum requirement)
Distribution provided: 753.98 mm²/m (140% of minimum requirement)
Steel consumption: 54.4 kg/m³88.18 ÷ 1.62 = 54.4 kg/m³
Equivalent Stock Bars by Diameter
12 mm: 6 bars (56.82 kg)
16 mm: 2 bars (37.54 kg)
Approximate results for planning only. Verify with a professional.
Looking for the verification checklist, reference tables, tips, or common mistakes?See the complete Footing Steel Calculator.
Footing reinforcement planning
This page includes heavier bottom steel and a lighter optional top mesh.
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: 2.0 m x 1.8 m.
- Top mesh included.
- Wastage: 7%.
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
| Input | Value |
|---|---|
| Footing Type | Isolated / Pad Footing |
| Length | 2000 mm |
| Width | 1800 mm |
| Thickness | 450 mm |
| Cover | 75 mm |
| Count | 1 |
| Top Mesh | Included |
| Wastage | 7% |
Step 1 — Effective Dimensions
Step 2 — Bar Groups & Weight
| Bar Type | Count | Cutting Length | Total Length | Weight |
|---|---|---|---|---|
| Bottom Main bars (16 mm @ 150 mm) | 12 | 1.85 m | 22.2 m | 35.08 kg |
| Bottom Distribution bars (12 mm @ 150 mm) | 14 | 1.65 m | 23.1 m | 20.53 kg |
| Bottom Steel | 55.61 kg | |||
Step 3 — Top Mesh
| Bar Type | Count | Total Length | Weight |
|---|---|---|---|
| Top Main bars (12 mm @ 200 mm) | 10 | 18.5 m | 16.44 kg |
| Top Distribution bars (12 mm @ 200 mm) | 11 | 18.15 m | 16.13 kg |
| Top Steel | 32.57 kg | ||
Step 4 — Net Steel, Wastage & Procurement
| Component | Quantity |
|---|---|
| Net Steel | 88.18 kg |
| Wastage (7%) | 6.17 kg |
| Total to Procure | 94.35 kg |
| Concrete Volume | 1.62 m³ |
| Steel Consumption | 54.4 kg/m³ |
Therefore, for 1 isolated / pad footing the estimated footing mesh steel is 88.18 kg net and 94.35 kg for procurement including 7% wastage.
Cross-check against the Quick Reference Tables in the complete Footing Steel Calculator.