Slab & Shed Base Cost Calculator
Build a transparent estimate for a slab or shed base, separating quantity bases, priced lines, unknown prices and excluded work.
Part of the Concrete & Masonry calculators — see all tools in this category.
Slab and shed base cost estimate
Price measured quantities and quotes by stated scope, keeping selected quantities, missing prices and exclusions visible.
Preparing calculator controls…
| Base material | $120.00 |
|---|---|
| Formwork | $80.00 |
| Membrane | $100.00 |
| Reinforcing mesh | $120.00 |
| Concrete | $300.00 |
| Labor | $400.00 |
| Excavation | Excluded |
| Disposal | Excluded |
| Rebar | Excluded |
| Delivery | Excluded |
Current result
Estimated total: $1,120.00
A net quantity is the installed/takeoff amount; an ordered or purchased quantity already includes any supplier stock rounding applied upstream. This worksheet prices exactly the stated basis and does not round it again. Confirm stock packs, waste and supplier ordering in the source takeoff. Excluded scopes are not free, and a blank selected rate is incomplete—not zero—so totals omit those lines.
- Blank prices are unpriced and do not contribute zero to the estimate.
- No construction layout, reinforcement design, supplier stock size, or disposal method is inferred from this cost worksheet.
- Metric tonnes and US short tons remain distinct price bases.
Estimated total: $1,120.00
Cost breakdown
| Line | Purchased quantity / unit / basis | Pricing state | Direct price | Entered line tax |
|---|---|---|---|---|
| Base material | 3,000 kg (ordered) | Priced | $120.00 | $0.00 |
| Formwork | 8 count (ordered) | Priced | $80.00 | $0.00 |
| Membrane | 2 count (ordered) | Priced | $100.00 | $0.00 |
| Reinforcing mesh | 4 count (ordered) | Priced | $120.00 | $0.00 |
| Concrete | 2 m³ (ordered) | Priced | $300.00 | $0.00 |
| Labor | — | Priced | $400.00 | $0.00 |
| Excavation | — | Outside selected scope | — | — |
| Disposal | — | Outside selected scope | — | — |
| Rebar | — | Outside selected scope | — | — |
| Delivery | — | Outside selected scope | — | — |
- Direct priced subtotal
- $1,120.00
- Selected contingency base
- $1,120.00
- Contingency rate
- 0%
- Contingency amount
- $0.00
- Before-tax total
- $1,120.00
- Entered line tax
- $0.00
- Contingency tax (not entered)
- $0.00
- Final total
- $1,120.00
Cost by category
| Category | Cost | State |
|---|---|---|
| Base material | $120.00 | priced |
| Formwork | $80.00 | priced |
| Membrane | $100.00 | priced |
| Reinforcing mesh | $120.00 | priced |
| Concrete | $300.00 | priced |
| Labor | $400.00 | priced |
| Excavation | Not priced | excluded |
| Disposal | Not priced | excluded |
| Rebar | Not priced | excluded |
| Delivery | Not priced | excluded |
How it works and assumptions
Choose an itemized scope to enter an upstream net or ordered quantity with its compatible rate, a fixed fee, or an explicit exclusion. Alternatively use a single all-in quote only when it covers every detailed scope.
This is a cost worksheet, not a construction design. Use the live Itemized Slab & Shed Base Estimate guide to keep upstream footing, formwork, mesh and membrane takeoffs separate and manually enter only compatible quantities; the guide does not transfer results or create an exporter.
Worked example
The calculator includes an independent example that differs from the C15 UAT fixture: 5 m³ of concrete at $142/m³ plus $275 delivery, before tax or contingency.