Example engineering calculations
Worked, unit-aware calculation worksheets across structural, mechanical, electrical and more. Open any example into your own workspace to edit and reuse. New to Calculeaf? Start with your first worksheet or the examples guide.
515 examples
Net Positive Suction Head Available (NPSHa)
The net positive suction head available at a pump's suction, the margin above vapor pressure that keeps the pump from cavitating.
Cavitation Number
A dimensionless index comparing the local pressure margin above vapor pressure to the flow's dynamic pressure, used to assess cavitation risk.
Control Valve Flow Coefficient (Kv, Metric)
The metric flow coefficient Kv of a control valve, derived from its flow rate, fluid specific gravity, and pressure drop.
Pump Specific Speed (Dimensionless Index)
A shape-classifying index for centrifugal pumps computed from the plain numeric rpm, gpm, and feet-of-head values at the best efficiency point.
Pump System Curve Operating Head
The total dynamic head a pump must overcome at a given flow, combining a fixed static lift with head loss that grows with the square of flow rate.
Series Pump Combination Total Head
The combined head produced by two pumps piped in series, each passing the same flow but adding its own head rise.
Parallel Pump Combination Total Flow
The combined flow delivered by two identical-head pumps piped in parallel, each contributing its own share of flow at a common head.
Sluice Gate Discharge
The flow rate passing beneath a partially raised sluice gate as a function of gate opening, width, discharge coefficient, and upstream head.
V-Notch (Triangular) Weir Flow Rate
The flow rate over a triangular V-notch weir as a function of notch angle and upstream head, a standard method for measuring small open-channel flows.
Siphon Discharge Velocity
The theoretical outlet velocity of a siphon driven purely by the elevation difference between the reservoir surface and the outlet.
Trapezoidal Channel Cross-Sectional Area
The wetted cross-sectional area of a trapezoidal open channel from its bottom width, flow depth, and side slope.
Air Duct Friction Pressure Loss (Darcy-Weisbach)
The pressure drop along a straight run of HVAC ductwork from air friction against the duct walls, using the same Darcy-Weisbach form used for pipe flow.
Two-Phase Flow Quality
The vapor mass fraction (quality) of a two-phase liquid-vapor mixture, defined as vapor mass flow divided by total mass flow.
Pile Skin Friction Capacity
The load a driven or bored pile can carry through side friction between its shaft surface and the surrounding soil.
Pile End-Bearing Capacity
The load a pile can carry at its tip, from the bearing capacity of the soil or rock beneath the pile base.
Pile Group Efficiency (Converse-Labarre)
The reduction in average per-pile capacity when piles are grouped closely together, due to overlapping stress zones between adjacent piles.
Infinite Slope Stability Factor of Safety (No Seepage)
The factor of safety against sliding on a plane parallel to an infinite (long, uniform) slope, with cohesion and friction resisting gravity-driven shear.
Coulomb Active Earth Pressure Coefficient
The active earth pressure coefficient for a cohesionless soil retained behind a wall, from the simplified Coulomb (Rankine-form) relation.
Dry Density from Wet Density and Water Content
The dry unit weight of a soil sample computed from its measured wet (bulk) unit weight and gravimetric water content.
Consolidation Time Factor
The dimensionless time factor governing the rate of primary consolidation settlement in a saturated clay layer.
Cyclic Stress Ratio for Liquefaction Screening (Simplified)
A simplified estimate of the earthquake-induced cyclic shear stress ratio used as the demand side of a liquefaction triggering assessment.
Terzaghi Bearing Capacity (Strip Footing)
The ultimate bearing capacity of a strip footing on cohesive-frictional soil from Terzaghi's classical three-term superposition equation.
Elastic Settlement of a Footing on Sand (Simplified)
An estimate of immediate elastic settlement for a footing bearing on sand, using bearing pressure, footing width, an influence factor, and soil modulus.
Fracture Mechanics Stress Intensity Factor
The stress intensity factor at the tip of a crack in a loaded component, the central quantity in linear elastic fracture mechanics.