Concrete Job Estimate & Profit Calculator

What this calculator does

Most concrete calculators stop at cubic yards. A bid needs much more: what the supplier will actually bill after rounding, delivery and short-load fees, base and forms, reinforcement, crew time, overhead, and the profit you need. This tool takes a concrete job from dimensions to a customer price and shows exactly where every dollar goes.

Inputs explained

• Sections — each rectangular area (slab, footing, walkway) with its own length, width, and depth. Volumes are calculated separately, then added together.
• Waste allowance — extra concrete for uneven base, over-dig, and spillage.
• Supplier increment — the smallest unit your supplier sells. The order is rounded up to it.
• Concrete price, delivery, short-load fee — from your supplier quote.
• Labor — total crew hours at your burdened cost per hour.
• Site prep, base, reinforcement, forms, finishing, equipment, permits, disposal, other — direct job costs. Enter zero for anything that doesn't apply.
• Overhead and margin — your share of company overhead and the profit you want as a share of the price.

Formulas

1. Section yd³ = length ft × width ft × (depth in ÷ 12) ÷ 27
2. Raw volume = sum of all sections
3. Volume with waste = raw × (1 + waste% ÷ 100)
4. Order quantity = volume with waste, rounded UP to the supplier increment
5. Concrete cost = order quantity × price per yd³
6. Direct costs = concrete + delivery + short-load + labor + site prep + base + reinforcement + forms + finishing + equipment + permits + disposal + other
7. Overhead = fixed amount or direct costs × overhead%
8. Total cost = direct costs + overhead
9. Customer price = total cost ÷ (1 − margin)
10. Profit = price − total cost

Waste and supplier rounding

Waste and rounding are two separate steps, applied in order. Waste is your estimate of concrete you'll actually lose on site. Rounding reflects how the supplier sells it. For example, 2.47 yd³ plus 10% waste is 2.72 yd³; with a 0.25 yd³ increment, you order and pay for 2.75 yd³. Adding a big waste factor and rounding to a whole yard can over-order a small job significantly, so set both deliberately.

Worked example

Volume check: a 20 × 10 ft patio at 4 in is 20 × 10 × 0.333 = 66.67 ft³, or 2.4691 yd³. With 10% waste that's 2.7160 yd³, rounded to 2.75 yd³ at a 0.25 increment. At $180/yd³ the concrete costs $495.

Full job (the "Load example values" job): add a 15 × 4 ft walkway at 4 in (0.74 yd³). Total raw volume is 3.21 yd³, or 3.53 yd³ with waste, so you order 3.75 yd³ for $675. Then add:

• $125 delivery and a $75 short-load fee
• 16 crew hours at $45 = $720
• $300 site prep and $180 base
• 20 rebar sticks at $9 = $180
• $120 forms, $60 finishing, $150 equipment, $80 disposal

Direct costs total $2,665. Adding 10% overhead ($266.50) gives a total cost of $2,931.50. At a 25% margin the price is $2,931.50 ÷ 0.75 = $3,908.67, for a profit of $977.17.

Assumptions

• Every section is a simple rectangle of uniform depth. Break irregular shapes into rectangles.
• All sections share one mix and one supplier order.
• Prices are your own quotes, before sales tax.

Limitations

• It does not design or specify concrete mixes, reinforcement, thickness, or base. Follow your plans, engineer, and local code.
• It doesn't model thickened slab edges, round piers, stairs, or sloped surfaces.
• It doesn't include pump truck minimums, cold- or hot-weather additives, or overtime unless you enter them as costs.
• The price is cost-based. Your local market may support a different number.