Design Calculators

Live calculations tied to AISC, ACI, ASCE 7, AASHTO, and FHWA equations — no spreadsheet required.

Steel Beam Design (LRFD)

AISC 360-22 / ASCE 7-22

Dead load (klf)

Live load (klf)

Span (ft)

Yield strength (ksi)

Factored load wu: 2.64 klf1.2D + 1.6L
Design moment Mu: 297 kip·ftwu L² / 8
Design shear Vu: 39.6 kip
Required Zx: 79.2 in³Mu·12 / (φb Fy), φb = 0.90
Deflection limit L/360: 1 in

Steel Column Capacity

AISC 360-22 Chapter E

Gross area (in²)

Radius of gyration (in)

Effective length factor K

Unbraced length (ft)

Fy (ksi)

Slenderness KL/r: 66.9
Elastic buckling Fe: 63.89 ksi
Governing branch: Inelastic (0.658^(Fy/Fe))
Fcr: 36.03 ksi
φcPn: 476.7 kipφc = 0.90

RC Beam Flexure

ACI 318-19

Tension steel As (in²)

fy (ksi)

f′c (ksi)

Width b (in)

Effective depth d (in)

Stress block a: 4.41 inAs fy / (0.85 f′c b)
β1: 0.85
Neutral axis c: 5.19 in
Steel strain εt: 0.0094Tension controlled
φ: 0.9
φMn: 260.5 kip·ft

Bolt & Fillet Weld Capacity

AISC 360-22 J2/J3

Bolt diameter (in)

Number of bolts

Bolt Fnv (ksi)

Weld leg size (in)

Total weld length (in)

FEXX (ksi)

Bolt area Ab: 0.442 in²
φRn bolts (shear): 71.6 kipφ = 0.75, single shear
φRn weld: 66.8 kip0.75(0.60 FEXX)(0.707w)L
Governing: Weld

Shallow Foundation Bearing Capacity

Meyerhof / FHWA-NHI-16-009

Cohesion c (psf)

Friction angle φ (deg)

Unit weight γ (pcf)

Footing width B (ft)

Embedment Df (ft)

Factor of safety

Nc: 35.49
Nq: 23.18
Nγ: 30.21
Surcharge q: 480 psf
qult: 22,002 psf
qall: 7,334 psfFS = 3

Consolidation Settlement

Terzaghi 1-D consolidation

Compression index Cc

Layer thickness H (ft)

Initial void ratio e0

σ′0 (psf)

Δσ (psf)

cv (ft²/day)

Settlement Sc: 0.338 ft (4.05 in)
Drainage path Hdr: 5 ftDouble drainage assumed
t90: 424 daysTv = 0.848

Retaining Wall Stability

Rankine / AASHTO LRFD §11

Wall height H (ft)

Backfill γ (pcf)

φ (deg)

Wall + soil weight (lb/ft)

Base width (ft)

Base friction μ

Ka: 0.307
Active thrust Pa: 2,655 lb/ft
Overturning moment: 10,619 lb·ft/ft
FS sliding: 2.64OK (≥1.5)
FS overturning: 5.27OK (≥2.0)
Avg base pressure: 1,750 psf

Horizontal Curve

AASHTO Green Book

Design speed (mph)

Superelevation e (ft/ft)

Side friction f

Actual radius R (ft)

Deflection Δ (deg)

Minimum radius: 1,008 ftR provided OK
Tangent T: 344.1 ft
Curve length L: 670.2 ft
External E: 48.36 ft
Middle ordinate M: 46.49 ft

Vertical Curve (SSD)

AASHTO Green Book

Grade in g1 (%)

Grade out g2 (%)

Sight distance S (ft)

Crest = 1, Sag = 0

Algebraic difference A: 5 %
Curve type: Crest
L (assume L > S): 753 ft
Governing L: 753 ftL > S case controls
K = L/A: 150.6

Manning Open Channel

FHWA HEC-22

Manning n

Bottom width b (ft)

Flow depth y (ft)

Side slope z (zH:1V)

Channel slope S (ft/ft)

Area A: 27.5 ft²
Wetted perimeter P: 17.18 ft
Hydraulic radius R: 1.601 ft
Discharge Q: 131.8 cfs
Velocity V: 4.79 ft/s
Froude number: 0.644 (subcritical)

Rational Method & Storm Drain

HEC-22 / TR-55

Runoff coefficient C

Rainfall intensity i (in/hr)

Drainage area A (acres)

Pipe diameter (in)

Pipe n

Pipe slope (ft/ft)

Peak flow Q: 37.8 cfsQ = C i A
Pipe full capacity: 16 cfs
Full-flow velocity: 5.09 ft/s
Adequacy: UNDERSIZEDQ/Qfull = 2.36

Weir & Orifice Outlet

HEC-22 detention outlets

Weir coefficient Cw

Weir length (ft)

Head over weir (ft)

Orifice coefficient

Orifice area (ft²)

Head on orifice (ft)

Weir discharge: 35.02 cfsQ = C L H^1.5
Orifice discharge: 3.37 cfsQ = C A √(2gh)
Combined outflow: 38.39 cfs

Wind, Snow & Seismic Loads

ASCE 7-22

Basic wind speed V (mph)

Gust factor G

Ground snow pg (psf)

Seismic weight W (kip)

Seismic coefficient Cs

Velocity pressure qz: 24.46 psf0.00256 Kz Kzt Kd V²
Design wind pressure p: 16.63 psfqz G Cp (external only)
Flat roof snow pf: 18.9 psf0.7 Ce Ct Is pg
Seismic base shear V: 216 kipV = Cs W

Concrete, Steel & Tributary Quantities

Estimating

Bay length X (ft)

Bay length Y (ft)

Slab thickness (in)

Steel beam weight (plf)

Total beam length (ft)

Superimposed load (psf)

Bay area: 750 ft²
Concrete volume: 18.5 yd³+5–8% waste
Slab self weight: 100 psf
Structural steel: 5.52 tons
Tributary load on bay: 75 kip

Engineering Calculators