Construction Waste Calculator
Waste volume and disposal (dumpster size) for a demolition or build.
Result appears here
Fill in the fields and press Calculate.
Formula, calculation, assumptions and sources
Area mode: loose volume = area × debris depth × bulking factor (1.4)
Volume mode: loose volume = removed volume × bulking factor
Dumpster = next standard size (10 / 20 / 30 / 40 yd³) ≥ loose volume with waste
Run the calculation to see each step with your own numbers.
400 ft² roof, single-layer tear-off, 15% waste.
Loose = 400 ft² × 2 in × 1.4 bulking = 93 ft³ = 3.5 yd³ → 4.0 yd³ with waste
Weight ≈ 0.9 tons (light) — but shingles run ~2–3× that; check the box weight limit
Dumpster = 10 yd³ box
- Depth factors are rough loose-debris averages for each demo type — a real tear-off varies with the structure. Verify against the actual materials.
- Weight assumes light mixed C&D at ~500 lb/yd³. Concrete (~2,000–4,000 lb/yd³), soil, brick and asphalt shingles are far heavier and are usually billed by tonnage, not box size — and many boxes have a weight limit.
- Dumpster fill is assumed reasonably efficient; bulky, un-broken items waste box space.
- Hazardous materials (asbestos, lead paint) are not ordinary C&D debris and must be handled separately.
- What size dumpster do I need?
- For a single room refresh, a 10-yard box is usually plenty. A whole-house gut or a roof tear-off is typically 20–30 yards. When the debris is heavy — concrete, dirt, plaster, shingles — the limit is weight, not volume, so ask the hauler about tonnage caps and consider multiple smaller pulls.
- What is a bulking factor?
- Material takes up more room broken out than in place — a demolished stud wall is 1.3 to 1.5 times its in-place volume, lath and plaster up to twice. The calculator applies it so the box is sized for the pile, not the wall.
- One big box or two small ones?
- Two smaller pulls often cost less than one oversized box and let you keep working while the first is hauled. They also help when heavy debris would put a single big box over its weight limit.
Method
Loose volume = footprint × loose-debris depth × bulking (swell) factor. Bulking factors and mixed-C&D unit weight (~500 lb/yd³) from EPA C&D materials guidance and demolition-estimating practice. Standard geometry otherwise.
About the Construction Waste Calculator
The Construction Waste Calculator estimates the loose debris volume from a demolition or renovation — from the project area and a debris-depth factor, or from a known volume of material and a bulking factor — then rounds up to a standard 10, 20, 30 or 40-yard roll-off. Heavy debris such as concrete, soil, brick and shingles is usually limited by weight, not box size, so check the hauler's tonnage cap for those.
What you enter
- Estimate from
- Project / demolition area
- What's being removed
- Volume being removed (loose)
- Bulking / swell factor — Debris takes up more room broken out than in place. 1.3–1.5 for mixed C&D; up to 2 for lath and plaster.
- Waste allowance — Default 15%. Adjust to your own allowance — the exact figure is always shown too.
What you get back
- Loose debris volume — shown as the exact figure and, separately, a recommended figure with your waste allowance added.
- Approx. debris weight — Mixed C&D debris ≈ 400–600 lb/yd³; this uses 500. Concrete, dirt and shingles are much heavier — book by weight for those.
- Roll-off dumpster size (yd³) — Rounds up to a standard 10, 20, 30 or 40 yd³ box. Two smaller pulls can beat one oversized box.
The formula, a worked example, the assumptions behind it and the sources are shown in full below the calculator.
Related calculators
- Construction Material Calculator — General material estimate for a project from area or volume and a coverage rate.
- Roof Shingle Calculator — Shingle bundles and roofing squares for a roof of a given surface area.
- Cubic Yard Calculator — Convert a length, width and depth into cubic yards, cubic feet or cubic metres.
- Concrete Calculator — How much concrete a rectangular slab or footing needs, in cubic yards or cubic metres.
Part of the Additional Construction calculators.