Civil Engineering Calculators for Construction and Site Work

Use these civil engineering calculators to estimate materials, dimensions, and loads for construction and site projects. Find concrete quantities with Concrete Volume, Concrete Footing Volume, and Concrete Mix Ratio. Plan finishes and paving with Cement and Sand for Plastering, Floor Tile Estimator, and Number of Paving Stones.For structural and earthwork estimates, explore Maximum Floor Live Load Capacity, Cantilever Beam with Uniform Load, and Earthwork Cross Section Volume. Rafter Length and Floor Space Index (FSI) help with building layout and planning. These tools are for engineers, contractors, estimators, and DIY builders preparing project quantities; structural results should be checked by a qualified professional.

Wind Load

Estimate the dynamic wind pressure and total wind force on any exposed surface, such as a wall, sign, panel or structure. Enter the wind speed, air density, exposed area and shape coefficient to get pressure in Pa and force in N and lbf.

Earthwork Cross Section Volume

Estimate earthwork volume between two cross sections using the average end area method. Enter the two cross-sectional areas and the distance between them to get the cut or fill volume.

Elevation Point of Vertical Curve

Find the elevation at any point along a parabolic vertical curve. Enter the distance from the PVC, the initial and final grades, the curve length, and the PVC elevation to get the exact elevation y in feet.

Rafter Length

Calculate rafter length from roof pitch (e.g., 6/12) or roof angle, with optional overhang. Enter span, overhang, and pitch or angle to get the exact rafter length in feet for cutting and framing.

Floor Tile Estimator

Estimate how many tiles you need for a room's floor plus skirting. Enter room and tile dimensions in mm, skirting height, door width and wastage percentage to get the exact tile count.

Floor Space Index (FSI)

Calculate the Floor Space Index (FSI), also known as Floor Area Ratio (FAR), by entering the total covered (built-up) area and the land area. A quick check for zoning compliance and development density.

Maximum Floor Live Load Capacity

Estimate the maximum stationary live load a concrete slab-on-grade can carry. Enter allowable fiber stress, slab thickness, subgrade reaction modulus, and modulus of elasticity to get the capacity in psf.

Active Earth Pressure

Calculate the Rankine active earth pressure on a retaining wall from the retained soil height, unit weight and friction angle. Enter H, γ and φ to get the active pressure coefficient Ka and the resultant lateral force Pa.

Number of Paving Stones

Estimate how many paving stones you need for a patio, driveway or walkway. Enter the area dimensions and the paver size to get the required quantity plus a recommended total with a 10% wastage allowance.

Runoff Flow

Estimate peak stormwater runoff from a small drainage area using the Rational Method Q = C·i·A. Enter the drainage area, design rainfall intensity and runoff coefficient to get the peak flow in L/s, m³/s, ft³/s and more.

Earthwork Cross Sectional Area

Enter the X and Y coordinates of the points that outline an earthwork cross section, and this calculator returns its area using the shoelace formula. Useful for surveyors and civil engineers estimating excavation, fill, and grading quantities.

Stair Rise and Run

Calculate the number of risers, actual riser height, number of treads and total run of a staircase. Enter the total rise, desired step height and tread depth to plan a comfortable, code-friendly stair layout.

Belt Length

Calculate the required belt length for a two-pulley drive from the pulley diameters and center distance. Supports open and crossed belt arrangements in metric or imperial units.

Cubic Yards of Rectangular Stepping Stones

Calculate the volume of rectangular stepping stones in cubic yards. Enter length, width, depth in inches and the number of stones to find how much concrete you need for one stone or the whole set.

Footing Bearing Pressure

Enter the vertical load and footing plan dimensions to find the average soil bearing pressure under the footing, and compare it against the allowable bearing pressure to see if the design is OK.

Cubic Yards of Circular Stepping Stones

Calculate the concrete volume of circular stepping stones in cubic yards. Enter the diameter, thickness and number of stones to find how much concrete you need for one stone or the whole batch.

Cubic Yards of Triangular Stepping Stones

Calculate the concrete volume of triangular stepping stones in cubic yards. Enter the base, height and depth of each stone plus how many you need, and get the volume of a single stone and the whole batch.