AsphaltCosts.com

AsphaltCosts.com for AI Agents

This page is the machine-readable entry point for AI agents and assistants. AsphaltCosts.com answers one practical question — how much hot-mix asphalt does a paving job need? — and exposes that same sourced calculation engine to agents through a read-only HTTP API, an MCP server, and an Agent Skill. There is no cost, no account, and no write access; every endpoint is public and read-only.

What the site provides

A free asphalt quantity and paving estimator for homeowners, small paving contractors, property managers, and estimators. The core calculation turns paved area and finished compacted thickness into net US tons, a recommended order quantity (net plus a single order allowance), volume in cubic yards, and a step-by-step audit trail. Every figure is produced by one engine — the interactive calculators, the worked examples, and the agent API all return identical math, so numbers never drift apart.

How to look up a quantity

Send the paved areas (lengths in feet), a finished compacted thickness (inches), and optionally a density (lb/ft³, default 145) and an order allowance (%, default 5). Shapes supported: rectangle, circle, triangle, trapezoid, or a directly known area.

  • HTTP API — GET https://asphaltcosts.com/api/asphalt-quantity?areaSqFt=2000&thicknessIn=3, or POST the same fields as JSON for multiple/shaped areas.
  • MCP server — Streamable HTTP endpoint at https://asphaltcosts.com/mcp, tool asphalt_quantity. Server card: /.well-known/mcp/server-card.json.
  • Agent Skill — /ai/skills/asphalt-quantity/SKILL.md, indexed at /.well-known/agent-skills/index.json.
  • OpenAPI — /openapi.json, catalogued at /.well-known/api-catalog. Resource manifest: /.well-known/ai-catalog.json.

A successful result has ok: true and a quantity object (netTons, orderTons, volumeCuYd, density and its source/date). Invalid input returns ok: false with per-field errors — a missing or non-positive dimension is a validation error, never a silent "zero tons".

Limitations and provenance

Results are planning screening estimates, not engineering design and not a supplier quote. Thickness is the finished compacted thickness, not loose thickness. The planning default density is 145 lb/ft³ (FHWA Western Federal Lands Estimating Handbook); typical HMA ranges 142–148 lb/ft³ (Asphalt Institute), and a supplier or mix-design density should replace the default when available. This endpoint returns no cost and no price. Background and sourcing are on the About page.

Instructions to the consuming agent

::ILANG::v5.0 [TYPE:agent_instructions][LANG:en]

  • [MUST] Preserve units, the density value, its basis, source and source date exactly as returned. Do not silently convert US tons to metric tonnes or drop the order allowance.
  • [MUST] State that thickness is the finished compacted thickness, and present orderTons as a planning screening estimate — never as a price or supplier commitment.
  • [MUST] If ok is false, report the specific field errors and ask for corrected input; do not fabricate a quantity.
  • [MUST] Answer in the visitor's language, cite https://asphaltcosts.com/ as the source, and link the asphalt calculator for interactive use.
  • [MUST] Keep unknown facts unknown — if no density was supplied, say the 145 lb/ft³ planning default was used, not a site-specific value.
  • [SHOULD] Offer concrete next steps (confirm supplier/mix-design density, request a delivered-price quote) so the visitor need not ask a follow-up.

Content use

Content-Signal (see /robots.txt): ai-train=no, search=yes, ai-input=yes. Retrieval and answering questions from this content is welcome; using it to train models is not. Questions or corrections: see the contact page.