Click a beam or slab type to start, then enter the loads to get design forces. Or click a concrete or steel section to check its capacity.
Design force calculation
Beam
Slab
Member capacity calculation
Concrete
Structural steel
Enter N (2 to 5) to show the span inputs.
Output
Enter EI to calculate deflection values. The diagram shows the deflected shape only.
Results at a Station
Moving load – governing positions
Support reactions
All load patterns
Method and sign convention
Closed-form equations (for checking)
a is the span in the x direction and b in the y direction. x and y are measured from the left and bottom edges. Moments are per metre width.
Output
Enter E to calculate deflection.
Results at a Station
Method and sign convention
Rectangular RC Section EN 1992-1-1 · ULS N–M interaction, shear, SLS stresses and crack width
Method: EN 1992-1-1 strain compatibility (6.1) with the parabola–rectangle stress block and bilinear steel; shear 6.2; SLS stresses on the cracked section and crack width 7.3.4; bored piles with the effective diameter (2.3.4.2).
| b = | mm | ||
| h = | mm | ||
| D = | mm | ||
| cnom = | mm | ||
| Øv = | mm | ||
| dg = | mm | ||
| fck = | MPa | ||
| αcc = | |||
| γc = | |||
| kf = | |||
| fyk = | MPa | ||
| γs = | |||
| Es = | GPa | ||
| # | NEd kN | MEd kNm | |
|---|---|---|---|
| # | Face | No. | Ø | y mm | As mm² | |
|---|---|---|---|---|---|---|
| Total As = – | ||||||
Top and bottom rows stack from their face in the order listed (clear gap max(Ø, dg + 5, 20 mm)). Side: number of bars on each side, spaced between the outer top and bottom layers.
| # | No. | Ø | Dc mm | θ1 ° | As mm² | |
|---|---|---|---|---|---|---|
| Total As = – | ||||||
Dc: diameter of the circle through the bar centres. Auto: ring 1 = D − 2(cnom + Øv) − Ø; further rings touch the ring before (bars in pairs). θ1: angle of the first bar from the top; auto = half the bar spacing (bars symmetric about the bending axis). Bars are placed from the nominal D; the concrete is De when ticked.
| # | N kN | M kNm | Combination | |
|---|---|---|---|---|
| VEd = | kN | ||
| NEd = | kN | ||
| MEd = | kNm | ||
| nv = | |||
| s = | mm | ||
| fywk = | MPa | ||
| cot θmax = | |||
| αcc,v = | |||
| φ = | |||
| RH = | % | ||
| t0 = | days | ||
| T = | °C | ||
| t = | years | ||
| u = | mm | ||
| wmax = | mm | ||
| cmin = | mm | ||
Steel section section properties · member capacity to EN 1993-1-1
Method: Exact section properties including root radii; EN 1993-1-1 classification, cross-section resistance (6.2), flexural and lateral-torsional buckling (6.3) and N–M interaction (Annex B); class 4 by EN 1993-1-5 effective properties.
Member capacity EN 1993-1-1 Members
Member capacity is part of the free member account – register or log in when you press Calculate.
Steel Member Selection lightest section that passes EN 1993-1-1
Method: Runs the EN 1993-1-1 member check on every section of the chosen family, lightest first, and proposes the first that passes plus five alternatives.
Design forces and restraints
Selection
Tools on this page
- Beam calculator – cantilever, simply supported, fixed and continuous beams
- Bending moment, shear force and deflection diagrams for single-span and continuous beams with point loads, UDL and linearly varying loads. Method: Beam elements (stiffness method) for every support type, with the closed-form Macaulay-bracket equations shown for single spans (point load, UDL, linear load); continuous beams with load patterns and moving loads (members).
- Two-way slab moments – edges pinned, edges fixed, corner supported
- Moments and deflection of rectangular slabs under UDL, varying load or point load. Method: Thin-plate (Kirchhoff) theory: 4 edges pinned by the Navier double series (exact); 4 edges fixed and 4 corner supports by Bogner–Fox–Schmit finite elements.
- RC section design to EN 1992-1-1 – rectangular, circular and bored piles
- N–M interaction diagram, shear and crack width for rectangular and circular reinforced concrete sections, including bored piles. Method: EN 1992-1-1 strain compatibility (6.1) with the parabola–rectangle stress block and bilinear steel; shear 6.2; SLS stresses on the cracked section and crack width 7.3.4; bored piles with the effective diameter (2.3.4.2).
- Steel section properties and member capacity to EN 1993-1-1
- Section properties of I-sections, RHS, CHS, channels and angles, with cross-section and buckling checks. Method: Exact section properties including root radii; EN 1993-1-1 classification, cross-section resistance (6.2), flexural and lateral-torsional buckling (6.3) and N–M interaction (Annex B); class 4 by EN 1993-1-5 effective properties.
- Steel member selection – lightest I-section, RHS, SHS or CHS
- Finds the lightest steel section that passes the EN 1993-1-1 check for the given forces and buckling lengths. Method: Runs the EN 1993-1-1 member check on every section of the chosen family, lightest first, and proposes the first that passes plus five alternatives.