Dumpster Size Calculator

The formula

chosen = (byVolume.size ≥ byWeight.size) ? byVolume : byWeight, where each is the smallest container whose cap covers the corresponding total

shingle weight and volume

250 lb and 0.33 cu yd per roofing square, per layer — multiplied directly by the number of layers being torn off, since each layer adds its own full weight and volume rather than a partial share.

concrete weight and volume

150 lb per cubic foot at the entered thickness, with the broken volume increased by a 1.4x bulking factor over the intact slab volume — broken concrete takes up more space in a container than the same concrete did as a solid slab.

totalTons / totalVolume

The sum of every debris category's weight and volume, converted to tons and cubic yards respectively — the two figures each container size is checked against independently.

byWeight / byVolume

The smallest standard container size whose included tonnage covers totalTons, and separately, whose cubic-yard size covers totalVolume — computed as two independent answers before either is chosen.

chosen container

The larger of byWeight and byVolume — whichever cap actually requires the bigger box governs the final size, and the page reports which one it was.

overage

totalTons minus the chosen container's included tonnage, floored at zero. A positive figure here is what a hauler typically bills as an extra per-ton overage charge on top of the base rental price.

Where these numbers come from

Asphalt shingles at 250 lb and 0.33 cu yd per square per layer

Commonly published tear-off debris figures used across dumpster-rental and roofing-disposal guidance. Actual weight varies with shingle type and moisture — a rain-soaked tear-off can run heavier than a dry one — so treat this as a planning figure rather than a scale-verified one.

Drywall at 51 lb per sheet, carpet and pad at 0.5 lb per sq ft

Commonly cited approximate weights for standard 1/2 in drywall sheets and residential carpet with pad, drawn from general waste-disposal and renovation planning references. Thicker drywall and denser carpet padding will run heavier than these figures.

Broken concrete at 150 lb per cubic foot, bulking 1.4x when broken

150 lb per cu ft is the commonly cited density for normal-weight concrete. The 1.4x bulking factor for broken concrete versus intact slab volume is a widely used rule of thumb in demolition estimating — actual bulking varies with how finely the concrete is broken up.

Standard container sizes at 10/20/30/40 cu yd with 2/3/4/5 tons included

Common dumpster-rental sizing and included-tonnage tiers used across the industry. Exact included tonnage and available sizes vary meaningfully by hauler and by region, so confirm the specific cap your rental quote lists before relying on this page's figures for a firm budget.

Worked examples

Common mistakes

• Sizing a dumpster by the volume of debris alone, without checking the included tonnage. This is exactly backwards on a roofing or concrete job, where weight caps out first while the box still has visible room left.
• Forgetting that multiple shingle layers multiply the tear-off weight directly. A two-layer tear-off on the same roof this page's first example used would weigh close to 5 tons, likely pushing the size up two tiers rather than one.
• Mixing broken concrete into a general debris dumpster instead of ordering a dedicated clean-fill or concrete box. Concrete's weight-to-volume ratio is so much higher than everything else on this page that it often makes more sense — and can cost less — as its own load.
• Assuming a bigger container always has proportionally more included tonnage. It doesn't — the standard tiers add roughly one ton per size step while the volume steps up by ten cubic yards, so tonnage becomes the binding constraint faster than the box size alone would suggest.
• Not accounting for wet or rain-soaked debris. A tear-off left uncovered overnight can weigh noticeably more than these dry-material figures assume, which matters most on jobs already close to a tonnage cap.

Shopping summary

What this page produces is a size and a weight estimate to quote against, not a purchase — call it in against a local hauler's actual size and tonnage tiers, since those vary by region and by company even though the general shape (bigger box, slowly rising tonnage cap) holds industry-wide.

On a job that's also bringing material in — fill dirt, gravel, new framing lumber — the bulk delivery calculator runs the same weight-against-volume logic from the other direction, for whatever's arriving rather than what's leaving.