Concrete takeoff software
In short
Concrete is priced by volume, but drawings give area and a thickness note — so the takeoff is area × thickness for slabs, and cross-section × length for footings, beams and columns. Solid Takeoff measures the areas and lengths on the PDF; you convert to m³ from the section thicknesses. Free to start.
The catch with concrete is that the plan shows shapes and the section shows depths — you need both. Measure the slab and foundation footprints, read thicknesses from the sections and notes, and combine them into volume.
Then add the things that ride alongside it: formwork (by area), reinforcement, and an over-order allowance you can't recover once the pour is short.
What you measure in a concrete takeoff
| Item | Unit | How you take it off |
|---|---|---|
| Slab volume | m³ | Slab area (m²) × thickness (from the section), per bay if thicknesses differ. |
| Foundations / footings | m³ | Cross-section area × trench/strip length. |
| Beams & columns | m³ | Section area × length; count columns and multiply. |
| Formwork / shuttering | m² | Measure the contact faces (edges, soffits, sides). |
| Reinforcement | t / m | From bar schedules where available; mesh by area. |
| Concrete finish / power-float | m² | Slab area needing a finish. |
Area × thickness — from two drawings
A 120 m² slab at 150 mm is 120 × 0.15 = 18 m³. Measure the area on the plan with Solid Takeoff, read the thickness off the section or the structural notes, and multiply. Where bays or zones differ in thickness, measure and calculate each separately and sum.
Foundations, ground beams and edge thickenings are cross-section × length — measure the run lengths on the plan and take the section dimensions from the details.
Formwork, rebar and over-order
Formwork is measured by the contact area — slab edges, beam sides and soffits, column faces — so it's an area/linear exercise separate from the volume. Reinforcement comes from bar schedules where you have them (by tonnage) or by area for mesh.
Add a sensible over-order allowance for spillage, levels and pump losses — you can trim a stack of boards, but you can't un-pour a short load.
Estimator's tips
- •Volume = area × thickness — always get the thickness from the section, not the plan.
- •Watch for different slab thicknesses per bay; calculate each and sum.
- •Footings/beams are cross-section × length — measure length on the plan, depth on the detail.
- •Formwork is a separate contact-area measurement, not part of the volume.
- •Add an over-order allowance; a short pour is far costlier than a few spare m³.
Frequently asked questions
How do I calculate concrete volume from a drawing?
Measure the slab or foundation area on the plan, then multiply by the thickness from the section (e.g. 120 m² × 0.15 m = 18 m³). Footings and beams are cross-section × length. Solid Takeoff measures the areas and lengths; you apply the thicknesses.
The plan only shows area — where's the thickness?
On the section drawing or in the structural/general notes, not the plan. Use that depth for the volume, and watch for different thicknesses per bay.
How do I take off formwork?
Measure the contact faces — slab edges, beam sides and soffits, column faces — as areas/lengths. It's separate from the concrete volume.
Is there free concrete takeoff software?
Yes — Solid Takeoff's free plan measures the areas and lengths you need (watermarked exports); do the area × thickness volume step from the totals.
Try it on your own plan — free
Open a PDF and measure in your browser. No card, no install, no CAD. Free plan forever.