Asphalt Patch Tonnage Calculator

Hot mix tonnage for trench restoration and patches: base and surface courses, T-patch cutback per the encroachment permit, waste factor, and truckloads. Runs entirely offline; inputs persist in this browser via localStorage.

Use limits: Tonnage assumes compacted, in-place density on plan dimensions. Ragged saw cuts, over-milling, subgrade undulation, and hand work around castings all eat mix beyond neat-line — that's what the waste factor is for, and on small patches it's a big percentage. Mix type, lift thicknesses, tack, and the cutback dimension come from the agency's encroachment permit / standard details, which govern.

Patch Geometry

Patch type

Length (ft)

Trench width (ft) Surface cutback beyond trench, EACH side (ft)

The "T": many agencies require 12 in. (or more) of surface course beyond each trench edge onto undisturbed pavement.

Base course depth (in) — trench width only Surface course depth (in) — full T width

Ordering

Compacted density (pcf)

140–150 pcf compacted is typical for dense-graded HMA; the mix design sheet has the real number.

Waste factor (%)

Truck capacity (tons)

Quantities

Base course	—
Surface course	—
Patch area (surface / pay)	—
Total to order (with waste)	—
Truckloads	—

How the Numbers Are Derived

The math

tons = area (sf) × depth (in) / 12 × density (pcf) / 2000

A convenient cross-check: at 145 pcf, one ton covers about 16.5 sf per inch of compacted depth — or ~110 lb per square yard per inch (the "110 rule" estimators use).

For the T-patch, the base course runs at trench width and the surface course at trench width plus the cutback on each side. The pay area shown is the surface (widest) footprint in SF and SY.

Field notes

Small patches have brutal waste percentages — a 10-ton minimum load against a 6-ton patch is 40% "waste" no matter how careful the crew is. Batch nearby patches into one paving day.
HMA loses workability with temperature; a long haul or a slow crew on a cold day means more raked-off, unusable mix. That's waste factor too.
Confirm whether the permit measures the patch by surface area (SY) or by tonnage tickets — keep the delivery tickets either way.
Milling the cutback instead of a second saw cut usually gives a better joint and a cleaner tack surface — if the permit allows it.

References

Agency encroachment permit / standard trench restoration details — governing dimensions and mix requirements.

Asphalt Institute MS-22, Construction of Quality Asphalt Pavements. https://www.asphaltinstitute.org/

Approved mix design — actual compacted density.