Fast independent checks
Free site engineering calculators for setting out, drainage and quantities.
Mobile-first coordinate, level, gradient and quantity tools for site engineers. No account, no upload and no installation required.
Ten launch tools
Choose a calculation
Start with the plot checker or use one of the focused coordinate, level, drainage and quantity calculators.
Plot Coordinate Checker
Check plot dimensions, diagonals, angles, parallelism and squareness from Easting/Northing coordinates.
Open calculatorChainage + Offset → Coordinate
Calculate an Easting and Northing from a two-point baseline, chainage and signed offset.
Open calculatorCoordinate → Chainage + Offset
Project a coordinate onto a two-point baseline and return chainage, signed offset and foot point.
Open calculatorBearing + Distance
Calculate whole-circle bearing, reverse bearing, coordinate deltas, midpoint and horizontal distance.
Open calculatorPolygon Area from Coordinates
Calculate closed polygon area, perimeter and centroid from pasted Easting/Northing coordinates.
Open calculatorDrainage Gradient + Inverts
Calculate pipe fall, ratio, percentage and depths, or design a downstream invert from a required gradient.
Open calculatorLevel Interpolation Schedule
Generate intermediate design levels at regular chainage intervals between two known levels.
Open calculatorTrench + Spoil Loads
Estimate trapezoidal excavation, loose spoil after bulking, mass and full lorry loads.
Open calculatorConcrete Volume
Calculate concrete for rectangular pours, circular slabs and cylinders with quantity, waste and bag yield.
Open calculatorGradient Converter
Convert instantly between 1:n ratio, percentage, angle in degrees and millimetres per metre.
Open calculatorMetric + US customary
Materials, stockpiles and unit conversions
Estimate common construction materials in tonnes or short tons and work in metres, feet, cubic metres or cubic yards.
Material Quantity by Area + Depth
Estimate Type 1, 6F2, asphalt, concrete, shingle, sand, topsoil and other material volumes, weights and loads.
Open calculatorStockpile Volume + Weight
Calculate cones, truncated cones, rectangular piles and windrows in cubic metres, cubic yards, tonnes and short tons.
Open calculatorConstruction Unit Converter
Convert length, area, volume, mass and density between metric, US customary and imperial units.
Open converterWhy this site
Useful first, monetised second
The tools are designed to solve real field problems without locking basic calculations behind an account.
Local processing
Coordinate and project inputs are handled by JavaScript on the device rather than submitted to a database.
Transparent formulas
Each page explains the convention and formula so results can be checked against project procedures.
Progressive web app
After the first online visit, the static tools can be installed and cached for use with an unreliable connection.
Site Engineer Field Pack
CSV templates, QA check sheets, field formulas and downloadable schedules.