📚 Data Sources

This library lists the authoritative references we rely on for densities, coverage rates, material yields, and best practices. Each calculator links back to relevant sources here, and each source below includes what we use it for, typical value ranges, and variance notes.

Last updated: 26 Oct 2025

How we select and use sources

  1. Prefer primary standards (e.g., test methods, specifications).
  2. Corroborate with ≥2 reputable references (DOT tables, manufacturer TDS).
  3. Document ranges (materials vary by region, gradation, moisture).
  4. Set conservative defaults and make them editable in tools.
  5. Review cadence: at least annually or when standards change.

See our Methodology

Standards & Codes

Concrete & Masonry — Density / Yield Methods

Standard

What we use it for: converting volume ↔ mass, bag yields, mix proportion checks.

Typical values & notes
  • Normal-weight concrete fresh density typically ~ 140–150 lb/ft³ (2240–2400 kg/m³).
  • Common 60-lb concrete bag yield ≈ 0.45 ft³ (varies by brand and slump).

Variance drivers: mix design, air content, moisture, placement method.

Region: US/International • Last verified: 2025-10

Roofing — Squares, Bundles, and Coverage Conventions

Standard

What we use it for: shingle coverage (1 square = 100 ft²), bundle counts, waste factors.

Typical values & notes
  • Most 3-tab and many architectural shingles: ~3 bundles per square (varies by brand).
  • Starter/hip & ridge have different coverage — accounted for in waste.

Variance drivers: shingle style/brand, exposure, roof complexity, pitch.

Region: US/Canada • Last verified: 2025-10

Transportation Agencies (DOT)

Hot-Mix Asphalt (HMA) — Typical Densities & Lift Thickness

DOT Table

What we use it for: asphalt tons from area & depth; compaction allowances.

Typical values & notes
  • Compacted HMA density often assumed near ~145 lb/ft³ (2320 kg/m³) for planning.
  • Common drive/path lifts: 1.5–3.0 in compacted thickness (project-specific).

Variance drivers: mix design, aggregate, temperature, roller pattern, local specs.

Region: US • Last verified: 2025-10

Aggregates — Gradation & Unit Weight Ranges

DOT Table

What we use it for: gravel/sand/stone densities, base course compaction assumptions.

Typical values & notes
  • Loose aggregate unit weight commonly ranges ~95–120 lb/ft³ (1520–1920 kg/m³).
  • Moisture and gradation materially affect bulk density and coverage.

Variance drivers: particle shape, fines content, moisture, compaction energy.

Region: US/International • Last verified: 2025-10

Manufacturer Technical Data Sheets (TDS)

Prebagged Concrete Mix — Yield per Bag

Manufacturer TDS

What we use it for: converting slab/post-hole volume to bag counts.

Typical values & notes
  • Common yields (approx.): 40-lb ≈ 0.30 ft³, 50-lb ≈ 0.375 ft³, 60-lb ≈ 0.45 ft³, 80-lb ≈ 0.60 ft³.
  • Yields vary with water content and placement; always verify on the bag/TDS.

Variance drivers: slump, entrained air, compaction, brand formulation.

Region: US • Last verified: 2025-10

Interior Wall Paint — Coverage per Gallon

Manufacturer TDS

What we use it for: paint gallons per coat; adjusting for porosity & sheen.

Typical values & notes
  • Typical coverage on smooth walls: ~350–400 ft²/gal per coat.
  • Rough/porous substrates, deep tints, and low-temp application reduce coverage.

Variance drivers: substrate, primer use, roller/airless method, VOC limits, sheen.

Region: US/International • Last verified: 2025-10

Trade Associations

Roofing Best Practices — Waste Factors & Ventilation

Trade Guide

What we use it for: baseline waste allowances for simple vs. complex roofs.

Typical values & notes
  • Waste allowances often start around 10–15%, higher for hips/valleys.

Variance drivers: roof geometry, starter/ridge details, patterning, local practice.

Region: US/Canada • Last verified: 2025-10

Concrete & Masonry — Placement & Curing Guidance

Trade Guide

What we use it for: sanity checks on slab thickness ranges and finishing assumptions.

Typical values & notes
  • Common residential slab thicknesses: 4–6 in (project-specific; follow local code).

Variance drivers: loads, climate, soil, reinforcement, local code and engineering.

Region: US/International • Last verified: 2025-10

Textbooks & Handbooks

Construction Math / Estimating References

Reference Book

What we use it for: geometric methods, takeoff conventions, unit conversions.

Typical values & notes

Reinforces formulas for area, volume, roof pitch geometry, board feet, and rounding to purchase units.

Region: International • Last verified: 2025-10

Internal Reference Tables (Published here)

We maintain and publish the following “quick tables” derived from the sources above. They are conservative planning values; adjust to match your supplier’s data.

Typical Densities (for planning)

Material Typical Density Metric Notes
Hot-Mix Asphalt (compacted) ~145 lb/ft³ ~2320 kg/m³ Use compaction factor +5–8% as needed
Crushed Stone / Gravel (bulk) ~95–120 lb/ft³ ~1520–1920 kg/m³ Depends on gradation, moisture
Sand (dry) ~90–110 lb/ft³ ~1440–1760 kg/m³ Moisture increases bulk density
Normal-Weight Concrete (fresh) ~140–150 lb/ft³ ~2240–2400 kg/m³ Yield depends on slump/air

Paint Coverage (smooth interior walls)

Product Type Coverage / Gallon (per coat) Metric Notes
Interior Latex (eggshell) ~350–400 ft² ~32–37 m² Prime porous surfaces; deep tints reduce coverage

Shingle Coverage (typical)

Item Coverage Notes
1 Square 100 ft² Base unit for roofing
Bundle (common) ~33.3 ft² ~3 bundles per square (varies by product)

These tables are for planning only. Always confirm with your supplier’s current data sheets and local specifications.

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