# PavementCalculator.com

## About
143 free construction calculators across 7 categories, plus 11 educational guides. Config-driven architecture — every calculator is defined as a data object, not custom code. No signup required. Imperial and metric support. Free forever.

## Categories
- [Pavement & Asphalt](https://pavementcalculator.com/calculators/pavement/)
- [Concrete](https://pavementcalculator.com/calculators/concrete/)
- [Aggregate & Landscaping](https://pavementcalculator.com/calculators/aggregate/)
- [Earthwork & Excavation](https://pavementcalculator.com/calculators/earthwork/)
- [Building Materials](https://pavementcalculator.com/calculators/building-materials/)
- [Unit Converters](https://pavementcalculator.com/calculators/converters/)
- [Cost Estimators](https://pavementcalculator.com/calculators/cost/)

## Key Pages
- [Homepage](https://pavementcalculator.com/)
- [All Calculators Index](https://pavementcalculator.com/calculators/)
- [Guides](https://pavementcalculator.com/guides/)
- [Privacy Policy](https://pavementcalculator.com/legal/privacy/)
- [Terms & Conditions](https://pavementcalculator.com/legal/terms/)
- [About Us](https://pavementcalculator.com/legal/about/)
- [Contact Us](https://pavementcalculator.com/legal/contact/)
- [Calculator Methodology](https://pavementcalculator.com/legal/methodology/)

## For AI Agents
- Every calculator outputs results as structured data (JSON via the calculate() engine)
- Search index at /search-index.json — JSON array of all calculators with id, title, category, keywords
- Sitemap at /sitemap.xml
- All pages include JSON-LD structured data: sitewide Organization, homepage WebSite, per-calculator WebApplication (with datePublished/dateModified), per-category CollectionPage/ItemList, FAQPage, and BreadcrumbList
- Unit conversion is handled client-side — the engine normalizes to SI canonical units internally
- Formulas are plain math expressions evaluated at runtime and shown to the user via "Show Work" on every calculator page

## Site Structure
All calculators follow this URL pattern: /calculators/[category]/[calculator-id]/
Category pages list all calculators in that category: /calculators/[category]/
Each calculator page includes: interactive calculator, formula explanation, step-by-step example, field tips, FAQ section, related calculators, and related guides
Guide pages follow: /guides/[category]/[guide-slug]/