# Asphalt Tonnage Calculator

> Converts a paved area and compacted thickness into asphalt volume and weight with the compacted density of hot-mix asphalt (default 145 lb/ft³ ≈ 2,322 kg/m³), reported in pounds, kilograms, US short tons and metric tonnes with a waste allowance. Planning estimate only.

- Calculator id: `asphalt-tonnage` · Category: Construction & Home (`construction`) · Tool name: `estimate_asphalt_tonnage`
- Canonical page: https://tttkmbb.com/construction/asphalt-tonnage · This document: https://tttkmbb.com/construction/asphalt-tonnage.md · JSON definition: https://tttkmbb.com/construction/asphalt-tonnage.json

## Purpose

Converts a paved area and compacted thickness into asphalt volume and weight with the compacted density of hot-mix asphalt (default 145 lb/ft³ ≈ 2,322 kg/m³), reported in pounds, kilograms, US short tons and metric tonnes with a waste allowance. Planning estimate only.

**Use when:** You need to order hot-mix asphalt by the ton for a driveway, parking area or path of known area and compacted thickness.

**Do not use when:** The pavement is concrete (use concrete-slab) or you need the aggregate base under it (use gravel); the exact density of a specific mix comes from the supplier's job-mix formula.

## Input

| Parameter | Type | Unit | Required | Description |
| --- | --- | --- | --- | --- |
| `area` | number | ft² or m² | required | Area to pave in ft² or m² (see area_unit). (> 0, max 10000000) |
| `area_unit` | enum: m2 \| ft2 |  | optional, default "ft2" | Unit of the area input; areas are reported in both m² and ft². |
| `thickness` | number | in or mm | required | Compacted lift thickness in inches or millimetres (see thickness_unit): 2–3 in (50–75 mm) for driveways, 4 in (100 mm) or more for roads and parking lots. (> 0, max 1000) |
| `thickness_unit` | enum: in \| mm |  | optional, default "in" | Unit of thickness. |
| `density` | number |  | optional | Compacted density of the mix in lb/ft³ or kg/m³ (see density_unit). Default 145 lb/ft³ (2,322 kg/m³), the usual estimating figure for dense-graded hot-mix asphalt. (> 0, max 5000) |
| `density_unit` | enum: lb_ft3 \| kg_m3 |  | optional, default "lb_ft3" | Unit of density. |
| `waste_percent` | number | % | optional, default 5 | Extra material for cuts, breakage and offcuts, applied as a multiplier (1 + waste_percent/100). 5 % covers an uneven base, hand work at edges and material left in the truck. (min 0, max 50) |

## Output

| Field | Type | Unit | Description |
| --- | --- | --- | --- |
| `volume_ft3` | number | ft³ | area × thickness. |
| `volume_m3` | number | m³ | Same volume in cubic metres. |
| `weight_lb` | number | lb | volume × density. |
| `weight_kg` | number | kg | Weight in kilograms. |
| `tons_us` | number | short tons | weight_lb / 2000. |
| `tonnes_metric` | number | t | weight_kg / 1000. |
| `with_waste_tons_us` | number | short tons | tons_us × (1 + waste_percent/100). |
| `with_waste_tonnes` | number | t | tonnes_metric × (1 + waste_percent/100). |

## Formula

`volume = area × thickness; weight = volume × density; tons_us = weight_lb / 2000; tonnes = weight_kg / 1000; order = weight × (1 + waste_percent/100). 1 lb/ft³ = 16.0185 kg/m³; 145 lb/ft³ ≈ 110 lb per yd² per inch of thickness.`

145 lb/ft³ (2.32 t/m³) is the conventional compacted density of dense-graded hot-mix asphalt (actual mixes run about 140–150 lb/ft³ depending on aggregate and air voids); asphalt is sold by weight, so the waste allowance covers base irregularities and yield loss. Planning estimate only; check quantities against the supplier's coverage figures and local code before ordering.

## Data Sources

- Wikipedia – Asphalt concrete — https://en.wikipedia.org/wiki/Asphalt_concrete (reference, retrieved 2026-09-24)
- Wikipedia – Asphalt — https://en.wikipedia.org/wiki/Asphalt (reference, retrieved 2026-09-24)

Data freshness: `static`. Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output.

## API

- `GET https://tttkmbb.com/api/v1/calculate/asphalt-tonnage?area=…&thickness=…`
- `POST https://tttkmbb.com/api/v1/calculate/asphalt-tonnage` with JSON body `{"inputs": {…}}`
- Response: unified envelope (`success`, `request`, `result.values`, `result.units`, `sources`, `freshness`, `timestamp`, `next_actions`, `links`); see https://tttkmbb.com/docs/response-format.md
- Schema: https://tttkmbb.com/api/v1/calculators/asphalt-tonnage · OpenAPI operationId `estimate_asphalt_tonnage` in https://tttkmbb.com/openapi.json
- Authentication: none. Rate limit: fair use, see https://tttkmbb.com/docs/rate-limits.md.

## MCP

- Server: `https://tttkmbb.com/mcp` (Streamable HTTP, JSON-RPC 2.0, no auth)
- Tool:  `run_calculator` with `{"calculator_id": "asphalt-tonnage", "inputs": {…}}`

## Example

- 1,000 ft² at 3 in, 145 lb/ft³, 5 % waste: inputs `{"area":1000,"area_unit":"ft2","thickness":3,"thickness_unit":"in","density":145,"density_unit":"lb_ft3","waste_percent":5}` → `{"volume_ft3":250,"volume_m3":7.079,"weight_lb":36250,"tons_us":18.125,"tonnes_metric":16.443,"with_waste_tons_us":19.031,"with_waste_tonnes":17.265}`
- 100 m² at 75 mm, 2,322 kg/m³, 5 % waste: inputs `{"area":100,"area_unit":"m2","thickness":75,"thickness_unit":"mm","density":2322,"density_unit":"kg_m3","waste_percent":5}` → `{"volume_m3":7.5,"volume_ft3":264.86,"weight_kg":17415,"tonnes_metric":17.415,"tons_us":19.197,"with_waste_tonnes":18.286}`

```
GET https://tttkmbb.com/api/v1/calculate/asphalt-tonnage?area=1000&area_unit=ft2&thickness=3&thickness_unit=in&density=145&density_unit=lb_ft3&waste_percent=5
```

## Limitations

The pavement is concrete (use concrete-slab) or you need the aggregate base under it (use gravel); the exact density of a specific mix comes from the supplier's job-mix formula. 145 lb/ft³ (2.32 t/m³) is the conventional compacted density of dense-graded hot-mix asphalt (actual mixes run about 140–150 lb/ft³ depending on aggregate and air voids); asphalt is sold by weight, so the waste allowance covers base irregularities and yield loss. Planning estimate only; check quantities against the supplier's coverage figures and local code before ordering. All values are computed from the formula above; no measurement or live data is involved.

## FAQ

**How thick should a driveway be?**

Typically 2–3 in (50–75 mm) of compacted asphalt over 6–8 in (150–200 mm) of compacted aggregate base for residential driveways; commercial lots use 3–4 in or more. Thickness is measured after compaction.

**Where does 145 lb/ft³ come from?**

It is the common estimating density for compacted dense-graded hot mix (≈ 2.32 g/cm³, or 110 lb per square yard per inch). Loose mix in the truck is lighter, but suppliers sell by weight.

## Related

- [Gravel Calculator](https://tttkmbb.com/construction/gravel.md) — Aggregate base under the asphalt.
- [Concrete Slab Calculator](https://tttkmbb.com/construction/concrete-slab.md) — Concrete alternative for the same area.
- [Density Calculator](https://tttkmbb.com/physics/density-mass-volume.md) — Weight from volume and density for other materials.