EzeStruct
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RC Beam Design
Bending, shear and serviceability to BS 8110-1:1997
ACI 318-19 active. Load factors: 1.2D+1.6L. φb=0.90 (flexure), φv=0.75 (shear). Vc=0.17λ√f'c×bw×d (§22.5.5.1). L/d limits: §9.3.1.
Section & Geometry
Characteristic Loading
Material Properties
Reinforcement
Results Summary
PASS
Full step-by-step calculation workingsShow ▼
Disclaimer: EzeStruct is a design aid. All results must be verified by a qualified engineer before use in construction.
EzeStruct™ Help & User Guide
Complete manual — v1.0
✕
Welcome to EzeStruct
EzeStruct is a free professional structural design calculator for civil and structural engineers worldwide. Seven modules, 10 international design codes, professional PDF export with BMD/SFD diagrams.
RC Beam
Simply supported, continuous multi-span (2–5 spans, Three-Moment Eq.), cantilever. Point loads supported. Bending, shear, deflection.
RC Slab
One-way, two-way (Table 3.14 + yield line), flat slab + punching shear.
RC Column
Rectangular (uniaxial + biaxial, slender) and circular sections.
Foundation
Pad, strip, raft, pile (single + group) and combined.
Retaining Wall
Cantilever RC and gravity walls. Rankine earth pressure.
Steel Beam
UB sections + custom. LTB, deflection, shear.
Steel Column
UC, CHS, SHS. Buckling, combined axial + bending.
Tip
New to EzeStruct? Click Quick start in the sidebar for a 5-step guide to your first calculation.
EzeStruct v2.0 | © 2026 Christian Okwudili Eze | ezestruct.com
Quick start — 5 steps
1
Select your design code
Use the RC Code and Steel Code dropdowns in the header. Choose from 5 RC codes (BS 8110, EC2, ACI 318, IS 456, AS 3600) and 5 Steel codes (BS 5950, EC3, AISC 360, IS 800, AS 4100). Load factors and formulas update automatically.
2
Choose your module
Click any tab in the navigation bar — RC Beam, RC Slab, RC Column, Foundation, Retaining Wall, Steel Beam or Steel Column.
3
Enter your parameters
Fill in geometry, loading and materials. Default values are provided — change only what you need.
4
Click Calculate
Results appear instantly — PASS/FAIL verdict, utilisation ratio cards and expandable step-by-step workings with full formula rendering.
5
Export as PDF
Click Export as PDF. A dialog confirms your project details and asks whether to include BMD/SFD diagrams. Click Export PDF to generate your professional A4 calculation sheet.
Pro tip
Fill in the ⚙ Project Details panel before starting. Your project name, engineer name, job number and company will appear on every PDF automatically.
Interface guide
Header bar
Logo, ⚙ Project Details, design code toggle, light/dark mode toggle and Help button.
Project Details panel
Click ⚙ to expand. Enter project name, client, company, job number, document number, engineer, checker, revision and company logo.
Navigation bar
Seven module tabs. Click to switch module. Inputs are preserved when switching.
Input panels
Left side of each module. Geometry, loading, materials and reinforcement fields with default values.
Results panel
Appears after calculating. PASS/FAIL verdict, metric cards, expandable workings and Export as PDF button.
Design code toggle
Switches the active code across all modules simultaneously. Load factors, partial factors and capacity formulas all update when you switch.
Note
Switching code clears current results. Re-run the calculation after switching.
RC Beam Design
Simply supportedContinuous (multi-span)Cantilever
Simply supported & Cantilever
1
Flexure — K value & lever arm
K = M/(bd²fcu). Checks K ≤ K' (0.156 for BS 8110/IS 456/AS 3600, 0.167 for EC2/ACI 318). Calculates lever arm z and required tension steel As,req. If K > K', doubly reinforced section with compression steel As2.
2
Point load — optional
Enter a characteristic point load P (kN) and its distance a (m) from the left support. Moment and shear are combined: M = wuL²/8 + Pu·a·b/L, V = wuL/2 + Pu·b/L. Leave P = 0 for UDL only. For cantilever, a is measured from the fixed end.
3
Shear — concrete capacity vc
BS 8110 Table 3.8 / IS 456 Cl.40.2: vc formula. EC2 Cl.6.2: vRd,c. ACI 318-19 §22.5.5.1: φvVc = 0.75×0.17λ√f'c×bw×d. AS 3600 Cl.8.2: 0.17√f'c.
4
Deflection — L/d ratio (all codes)
BS 8110 Table 3.10: simply=20, cantilever=7, continuous=26. EC2 Cl.7.4.2: simply=20, cantilever=8, continuous=26. ACI 318-19 §9.3.1: simply=16, cantilever=8, continuous=21. IS 456 Cl.23.2.1: simply=20, cantilever=7, continuous=26. AS 3600 Cl.8.5.4: simply=20, cantilever=7, continuous=24.
Continuous (multi-span) — Three-Moment Equation
Replaces single-span continuous. Solves 2–5 spans with unequal lengths, mixed UDL and point loads per span, and fixed or pinned end conditions. Works with all 10 design codes.
1
Structural analysis — Clapeyron's Three-Moment Equation
Exact solution for prismatic continuous beams. Builds a tridiagonal system of equations (one per interior support) and solves using the Thomas algorithm. Gives exact support moments M₀…Mₙ. The analysis is code-independent — the same bending moment diagram is used for all 5 RC codes.
2
Per-span loading
Each span has its own dead load Gk (kN/m), imposed load Qk (kN/m), and an optional point load P (kN) at distance a from the left end of that span. Leave P = 0 for UDL-only spans.
3
End conditions
Left and right end supports can be set independently to Pinned (M = 0) or Fixed. Fixed ends use the standard fixed-end moment as the boundary condition: M = wL²/12 + Pu·a·b·(L+b)/(6L).
4
RC design per span
After solving support moments, midspan sagging and support hogging moments are calculated per span. Each span is designed independently for the critical moment using the active design code — flexure (K, z, As), shear (vc) and deflection (L/d = 26 for BS/EC2/IS, 21 for ACI, 24 for AS 3600).
One-way slab — point load
The one-way slab also accepts an optional line load P (kN/m) and distance a (m) from the support. The moment and shear are combined with the UDL using the same approach as for beams.
Important
Cover is clear cover to main steel face (not to link). Effective depth: d = h − cover − link dia − bar radius. For ACI 318 / AISC 360, inputs and results are shown in imperial units (ft, in, kip, psi).
RC Slab Design
One-way slabTwo-way slabFlat slab
One-way slab
Spans in one direction (ly/lx > 2). Designed as a 1m wide strip. Checks main steel, secondary steel (minimum 0.13%bh), shear and deflection. Accepts an optional line load P (kN/m) at distance a from the support — combined with UDL for moment and shear.
Two-way slab
Spans both directions (ly/lx ≤ 2). Uses BS 8110 Table 3.14 moment coefficients or yield line theory. Checks bottom steel both directions and top steel at supports.
Flat slab
Supported on columns. Checks column strip (60% M) and middle strip (40% M) flexure. Punching shear checked at column face and 1.5d perimeter. Veff = 1.15 × wu × lx × ly.
Two-way tip
Ensure ly/lx ≤ 2 before using two-way design. If the ratio exceeds 2, use one-way design instead.
RC Column Design
RectangularCircular
Slenderness
Effective height le = β × lo is calculated for both axes. If le/h or le/b > 15 (BS 8110), the column is slender and additional moments Madd are added automatically.
Biaxial bending (rectangular)
For moments about both axes: Mx/Mux + My/Muy ≤ 1.0. Set My = 0 for uniaxial bending only.
End condition factors β
Both fixed β=0.75One fixed, one pinned β=0.85Both pinned β=1.0Unbraced β=1.2–1.5
Foundation Design
PadStripRaftPileCombined
Soil type dropdown
Selecting a soil type auto-populates a typical allowable bearing capacity qa. Always override with a site-specific value from a ground investigation report for real projects.
Pad foundation checks
1
Bearing (SLS unfactored)
q,max = N/A + 6M/BL² ≤ qa using characteristic loads.
2
Flexure (ULS factored)
Cantilever from column face using factored ULS pressure qu.
3
Punching shear at 1.5d
Critical perimeter u1 = 2(cx+cy) + 2π×1.5d.
Important
Always obtain a formal ground investigation report and have foundations checked by a qualified geotechnical engineer before construction.
Retaining Wall Design
Cantilever RC wallGravity wall
Cantilever wall
RC stem on base slab. Rankine Ka = (1−sinφ)/(1+sinφ). Checks: overturning FoS ≥ 2.0, sliding FoS ≥ 1.5, bearing ≤ qa. Structural: stem bending & shear, heel slab (sagging — bottom steel), toe slab (hogging — top steel). All to selected design code.
Gravity wall
Mass concrete or masonry. Relies on self-weight. Checks overturning, sliding, bearing and middle third rule (e ≤ B/6) to prevent tension under base.
Middle third rule
For gravity walls, the resultant must pass through the middle third of the base (e ≤ B/6). If this fails, widen the base or increase wall weight.
Steel Beam Design
11 UK Universal Beams (UB) and 34 AISC Wide Flange sections (W6 to W36) plus custom section input. Sections are grouped in the dropdown by region. Properties load automatically on selection.
Lateral torsional buckling (LTB)
Full restraint — no LTBIntermediate — reduced MbUnrestrained — full LTB
Deflection limits
Span/360 — floorsSpan/200 — roofsSpan/500 — sensitive finishes
Steel Column Design
Universal Column (UC)CHSSHS
Buckling check
Slenderness λ calculated for both axes. Perry-Robertson formula gives buckling reduction factor χ. Compressive resistance Pc = χ × py × Ag.
Combined interaction
F/Pc + Mx/Mcx + My/Mcy ≤ 1.0. Set My = 0 for uniaxial bending.
CHS and SHS
For CHS and SHS, EzeStruct calculates all section properties from outside diameter/width and wall thickness. No section tables needed.
PDF export
1
Run calculation first
Export only works after clicking Calculate and results are shown.
2
Pre-export dialog opens
Review and edit project details. Choose diagram options — BMD + SFD + load arrangement, BMD + SFD only, BMD only, or load arrangement only.
3
Click Export PDF
Calculation sheet opens in a new tab. Use Ctrl+P (or Cmd+P) → Save as PDF to save.
Pop-up blocker
If nothing happens, your browser is blocking pop-ups. Look for a notification in the address bar and allow pop-ups for ezestruct.com.
What the PDF contains
EzeStruct logo and crown, your company logo (if uploaded), all 10 project detail fields, PASS/FAIL verdict, metric cards, optional BMD/SFD diagrams, full step-by-step workings with professional formula rendering, disclaimer and footer.
Project details
Click ⚙ Project details in the header. Fill these fields once and they appear on every PDF you export.
Project name
e.g. “Bridge Rehabilitation Project”
Client name
e.g. “City Council”
Company
Your organisation
Project address
Site address or location
Job number
Internal project reference
Document number
Calculation document reference
Engineer name
Originator with qualifications
Checked by
Checker name
Revision
e.g. "Rev 01", "P1", "C1"
Company logo
PNG, JPG or SVG — appears on every PDF alongside EzeStruct branding
Design codes — 10 codes across RC and Steel
RC Codes (5)
BS
BS 8110-1:1997 — UK & Commonwealth
Load factors: 1.4Gk + 1.6Qk. Used in UK, Nigeria, Ghana, Kenya, Jamaica and other Commonwealth countries.
EC2
EN 1992-1-1:2004 — Europe & International
Load combination: 1.35Gk + 1.5Qk. γc=1.5, γs=1.15. Primary code in UK and all EU countries.
ACI
ACI 318-19 — USA, Canada & Middle East
LRFD: 1.2D + 1.6L. φb=0.90 (flexure), φv=0.75 (shear). Imperial inputs (ft, in, kip, psi). L/d limits per §9.3.1.
IS
IS 456:2000 — India & South Asia
Load factors: 1.5(DL + LL). γc=1.5, γs=1.15. Used across India and South Asian countries.
AS
AS 3600:2018 — Australia & New Zealand
Load combination: 1.2G + 1.5Q. φ=0.80 (flexure). Used in Australia, New Zealand and Pacific region.
Steel Codes (5)
BS
BS 5950-1:2000 — UK Steel
Load factors: 1.4Gk + 1.6Qk. py = 275 N/mm² (S275), 355 N/mm² (S355). UK UB/UC section tables.
EC3
EN 1993-1-1:2005 — European Steel
Load: 1.35Gk + 1.5Qk. γM0=1.0. S275/S355 grades.
AISC
AISC 360-22 — USA Steel (LRFD)
1.2D + 1.6L. φb=0.90 (bending), φc=0.90 (compression). 34 AISC W-sections (W6–W36) plus 11 UK UBs. A36/A992 grades.
IS
IS 800:2007 — India Steel
Load factors: 1.5(DL+LL). γm0=1.10. E250/E350 grades.
AS
AS 4100:2020 — Australia Steel
1.2G + 1.5Q. φ=0.90. Grade 250/350.
FAQ
Is EzeStruct really free? ▼
Yes — completely free, no credit card required. All seven modules and all 10 design codes (5 RC + 5 Steel) are available to all registered users.
Does EzeStruct work offline? ▼
Yes. Once loaded, all calculations run in your browser. No internet needed to calculate or export PDFs.
Can I use results for construction? ▼
EzeStruct is a design aid. All results must be independently verified by a qualified chartered engineer before use in construction or regulatory submissions.
Why is my calculation showing FAIL? ▼
Expand the step-by-step workings to see which check failed (shown in red). Typical fixes: increase section size, add more reinforcement, reduce span or reduce loading.
How does the multi-span continuous beam work? ▼
The Continuous (multi-span) sub-type uses the Three-Moment Equation (Clapeyron) — an exact structural analysis method for prismatic continuous beams. You define 2 to 5 spans, each with its own span length, dead load, imposed load, and optional point load. The end supports can be pinned or fixed. The analysis is code-independent — the same bending moment diagram is produced regardless of which RC code you are using. The RC design checks (load factors, shear capacity, L/d limits) then use your active code.
Can I add a point load to a beam or slab? ▼
Yes. Simply supported, continuous and cantilever beams all accept an optional point load P (kN) and its distance a (m) from the left support (or fixed end for cantilevers). One-way slabs accept an optional line load P (kN/m) at a specified distance. Leave P = 0 if you only have a UDL. Two-way and flat slabs do not support point loads — the Table 3.14 coefficients and flat slab theory only apply to area UDL.
What concrete and steel grades are available? ▼
Concrete: C8/10 (blinding, kerb bedding), C15/20 (light foundations), C20/25 (house foundations), C25/30, C30/37, C35/45, C40/50, C45/55, C50/60. Steel: 250 N/mm² (mild steel), 410 N/mm² (common in West Africa), 460 N/mm² (UK high yield), 500 N/mm² (EC2/AS/IS), 420 N/mm² (ACI Grade 60). Grades switch automatically with the active design code.
PDF export is not opening — what do I do? ▼
Your browser is blocking pop-ups. Look for a notification in the address bar and click Allow pop-ups for ezestruct.com. This only needs to be done once.
How do I save my calculations? ▼
Export as PDF — this is your saved record. EzeStruct does not currently save calculations between sessions. Saved calculations is planned for a future version.
Who built EzeStruct? ▼
Designed and built by Christian Okwudili Eze MCIOB, civil and structural engineer. Eze means King in Igbo — hence the crown. See the About page for more.
I found a calculation error — what do I do? ▼
Report it immediately to [email protected] with the module name, all input values and the result you believe is incorrect. Calculation errors are treated as urgent.
Units & code switching
How unit switching works
EzeStruct automatically switches input labels and default values when you change design code. No manual conversion needed.
SI codes
BS 8110, EC2, IS 456, AS 3600, BS 5950, EC3, IS 800, AS 4100 — all use mm, m, kN, kN/m, N/mm².
Imperial codes
ACI 318 and AISC 360 — inputs switch to ft, in, kip, psi. A red banner appears as a reminder.
Material labels
Concrete label changes to f'c (psi) for ACI. Steel changes to fy (psi). Dropdown options change to psi grades.
Bar notation
ACI uses # notation (e.g. #8). BS/EC2/IS/AS use T notation (T25).
L/d deflection limits by code
BS 8110 Table 3.10
Simply supported=20, Cantilever=7, Continuous=26
EC2 Cl.7.4.2
Simply supported=20, Cantilever=8, Continuous=26
ACI 318-19 §9.3.1
Simply supported=16, Cantilever=8, Continuous=21
IS 456 Cl.23.2.1
Simply supported=20, Cantilever=7, Continuous=26
AS 3600 Cl.8.5.4
Simply supported=20, Cantilever=7, Continuous=24
About the Founder
Christian Okwudili Eze MCIOB
UK-based Civil & Structural Engineer · Chartered Construction Manager
EzeStruct was founded by Christian Okwudili Eze, a UK-based civil and structural engineer and chartered construction manager with extensive experience delivering complex concrete and steel structures across infrastructure and energy projects.
EzeStruct was developed from hands-on engineering practice, with the aim of making transparent, code-compliant structural design and verification tools accessible to engineers worldwide. The platform is built around professional judgement, clear assumptions, and calculation traceability, supporting engineers in designing safely, efficiently, and responsibly across multiple international standards.
Trademark & legal
EzeStruct™ is a registered trademark — UK00004369086, Class 42. All rights reserved. EzeStruct is a design aid. All outputs must be independently verified by a qualified engineer before use in construction.
EzeStruct v2.0 | © 2026 Christian Okwudili Eze | ezestruct.com
Contact & support
CE
Christian Okwudili Eze MCIOB
Civil & Structural Engineer
ezestruct.com
ezestruct.com
When reporting a calculation issue, include:
1
Module and sub-type
e.g. "RC Slab — Two-way slab, continuous interior panel"
2
All input values
List every input field so the issue can be reproduced exactly.
3
Result EzeStruct gave
The specific value or check you believe is incorrect.
4
What you expected
Your manual calculation or the code clause reference.
Response time
We aim to respond within 48 hours. Calculation errors are investigated immediately.