Everyday calculators for civil and structural engineering practice - unit conversion, concrete mixes, rebar weights, beam analysis, slopes and drawing scales. Free, runs entirely in your browser, no sign-up.
Convert between SI, imperial and local units used in engineering - length, area, volume, force, pressure/stress, bending moment, mass, speed and temperature. Includes marla / kanal land units.
Cement, sand and aggregate quantities for nominal mixes (M10 to M25) by the standard dry-volume method - reported in bags, cft and m³ with a water estimate.
Steel weight for metric and US rebar sizes by length or by weight. Standard per-metre weights are shown in the quick table.
Maximum moment, shear and deflection for a simply supported beam under a uniformly distributed load (UDL) and / or a central point load.
Volumes for slabs, beams, columns, walls and footings with an instant cement-bag estimate at a 1:2:4 (M15) mix.
Convert road, ramp and drainage gradients between percent (%), degrees and 1:X ratios. Also computes slope from rise and run.
Convert between drawing-measured lengths and real-world distances for common CAD and architectural scales.
Area, moment of inertia, section modulus and radius of gyration for rectangular and circular sections.
Rough rebar requirement for a concrete volume by member type using typical kg/m³ ranges - for budgeting and BOQ sanity checks only.
Check a ramp gradient against common accessibility limits (ADA 1:12 and steeper local allowances).
Cut and fill volume between two cross-sections using the average end area method - the standard for roads, site grading and drainage earthworks.
Number of bricks and mortar volume for a wall, using Pakistani standard brick size (9" x 4.5" x 3") with mortar joints.
Cement and sand for wall and ceiling plaster by area, thickness and mix ratio - with the dry-volume allowance.
Volume and tonnage of asphalt for roads, driveways and pavements by area and compacted thickness.
Crush, bajri and sand needed for concrete and mortar by volume or by member quantities.
Break a BOQ item into material, labour and plant to justify a rate for extras and new items.
Approximate reinforcement weight for slabs, beams, columns and footings from member dimensions.
About 6.9 bags of 50 kg each (dry volume allowance 1.54, 5% waste). The mix calculator above reports it for any volume and mix.
Approximately 0.888 kg/m (using d²/162, where d is in mm). The rebar calculator covers all common sizes in kg/m, per-bar and totals.
Yes - 100% free, no sign-up, and everything runs in your browser. No files are uploaded anywhere.
These are reference and preliminary tools. Final structural design must follow applicable codes and be checked by a licensed engineer - contact Struc-Arch Pakistan for design support.
By cross-section. Each station gets a measured cross-section showing cut and fill areas; volume between adjacent sections uses the average end area method (V = L × (A1 + A2) / 2). Compacted fill shrinks, so the loose material needed is higher than the compacted volume - the earthwork calculator above handles both.
About 500 for Pakistani standard bricks (9" x 4.5" x 3") with mortar joints, plus 0.3 m³ of mortar. A 9" wall needs roughly 115 bricks per square metre of wall face (about 57 for a 4.5" half-brick wall).
About 11 m² at 12 mm thick with a 1:4 mix, and roughly 7 m² at 19 mm. The plaster calculator above reports exact cement and sand for any area, thickness and mix.
By tonne. Multiply the compacted volume by the asphalt density (about 2,350 kg/m³) and add 4-8% for wastage and overlaps. For a 100 m² driveway at 50 mm you need roughly 12 tonnes.
Beyond the free tools - structural design, quantity takeoffs, BOQs and fitness certification from a PMP / LEED-qualified team.
