Civil Calculators
Last updated: September 2026
Pipe Flow Velocity Calculator
Calculates the average flow velocity of fluid in a circular pipe given a volumetric flow rate and pipe diameter.
Water Pipe Flow Calculator
Calculate flow rate in a pressurized water pipe using the Hazen-Williams equation.
Pipe Flow Rate Calculator
Determine the flow rate of water through a pipe using the Hazen-Williams equation.
Pipe Flow Capacity Calculator
Determine water flow rate (in GPM) through circular pipes using Manning's equation.
Excavation Volume Calculator
Calculate the volume of earth to be removed for a rectangular excavation — foundation pit, trench, or basement cut.
Culvert Flow Capacity Calculator
Estimate the full-flow discharge capacity of a circular culvert using Manning's equation.
Concrete Mix Design Calculator
Estimate the total cement mass needed for a concrete batch based on target strength, volume, exposure conditions, and aggregate size.
Water Supply Pipe Sizing Calculator
Determine the minimum pipe diameter needed to deliver a required flow rate under specified pressure and elevation conditions.
Structural Beam Load Calculator
Estimate the load-bearing stiffness of a simply supported structural beam based on its span, cross-section, and material.
Pipe Flow Calculator (Hazen-Williams)
Determine water flow rate and velocity in pressurized pipes using the Hazen-Williams empirical equation.
Beam Deflection Calculator
Compute the maximum mid-span deflection of a simply supported beam under a uniformly distributed load (UDL) using δ = 5wL⁴ / (384EI).
Soil Bearing Capacity Calculator
Estimate the ultimate bearing capacity of soil beneath a square footing using Terzaghi's general bearing-capacity equation.
Retaining Wall Pressure Calculator
Computes the Rankine active lateral earth pressure resultant acting on a retaining wall based on soil height, unit weight, and internal friction angle.
Steel Weight Calculator
Calculate the total weight of steel reinforcement bars (rebar) given their diameter, length, and quantity.
Column Buckling Load Calculator
Calculates the critical (Euler) buckling load for a slender structural column given its material stiffness, cross-section, length, and end-fixity conditions.
Retaining Wall Design Calculator
Calculate active, passive, or at-rest lateral earth pressure on a retaining wall given soil properties, wall height, and surcharge loading.
Culvert Design Calculator
Size a circular or box culvert to pass a design stormwater discharge using Manning's equation.
Culvert Flow Calculator
Calculate the full-flow discharge capacity of a circular culvert using Manning's equation.
Pavement Thickness Design Calculator
Estimate the required pavement thickness for roads or parking lots based on traffic volume, subgrade strength, and design life.
Manhole Volume Calculator
Calculates the volume of concrete required to construct a circular manhole wall given the outer diameter, inner diameter, and height.
Flexible Pavement Thickness Calculator
Compute the required flexible pavement structural number using the AASHTO 1993 empirical design method.
Steel Reinforcement Calculator
Calculate the required tension steel reinforcement area (mm²) for singly reinforced concrete beams under a given design moment.
Earthwork Excavation Calculator
Estimate excavation volume, total cost, and number of truck loads needed for any construction dig.
Flexible Pavement Design Calculator
Calculate the required asphalt pavement layer thickness based on traffic loading (ESALs), subgrade strength (CBR), design reliability, and climate zone using the AASHTO flexible pavement method.
Storm Water Drainage Calculator
Estimate peak stormwater runoff and determine the minimum pipe diameter needed to handle it.
Column Buckling Calculator
Find the safe critical buckling load for a structural column using Euler's formula with a factor of safety.
Concrete Volume & Mix Calculator
Calculate how many cubic yards of concrete you need for a slab, footing, or pad, including a waste allowance.
Slope Stability Factor of Safety Calculator
Determine whether a soil slope is safe against sliding by computing the Factor of Safety (FS) using the simplified Bishop method.
Earthwork Volume Calculator
Compute the volume of soil to be cut or filled between two cross-sections on a construction site using the average end area method.
Slope Stability Calculator
Compute the factor of safety against sliding failure on an infinite slope using soil strength and groundwater parameters.
Earthwork Cut & Fill Calculator
Calculate the volume of soil to cut or fill when grading a site from an existing elevation to a target finish grade.
Culvert Sizing Calculator
Calculate the required culvert diameter to safely pass design stormwater flows under roads, driveways, or embankments.
Construction Cost Estimator
Estimate total construction costs for civil engineering projects by combining project area, construction type unit costs, a regional labor multiplier, and a contingency allowance.
Road Gradient Calculator
Calculates the gradient of a road or ramp as a percentage from the vertical rise and horizontal distance.
Foundation Bearing Capacity Calculator
Calculate the safe bearing capacity of a shallow foundation given soil properties and foundation geometry.
Concrete Volume Calculator
Estimate how many cubic metres of concrete to order for a rectangular slab, footing, or path.
Traffic Signal Timing Calculator
Determine the optimal signal cycle length and green time splits for a two-phase intersection.