Data Sources
This page lists the standards, codes, specifications, and references used across Calculator Shed’s tools. Each calculator page cites the specific sources relevant to its formulas and default values. This page provides a centralized reference library.
How We Select Sources
- Prefer primary standards: published test methods, specifications, and codes
- Corroborate with at least two independent sources (manufacturer TDS, DOT tables, trade association guides)
- Document value ranges, not single numbers — materials vary by region, gradation, moisture, and mix design
- Set conservative defaults and make them editable by the user
- Review at least annually or when standards are updated
Standards and Building Codes
Concrete and Masonry
- ASTM C150 / C150M — Standard Specification for Portland Cement
- ASTM C33 / C33M — Standard Specification for Concrete Aggregates
- ACI 318 — Building Code Requirements for Structural Concrete
- ACI 211.1 — Standard Practice for Selecting Proportions for Normal Concrete
Used for: concrete density, bag yield, mix design references, aggregate properties
Asphalt and Paving
- AASHTO M320 — Standard Specification for Performance-Graded Asphalt Binder
- AASHTO T166 — Bulk Specific Gravity of Compacted Asphalt Mixtures
- Asphalt Institute MS-2 — Asphalt Mix Design Methods
Used for: HMA density defaults, compaction factors, lift thickness guidelines
Electrical
- NFPA 70 (NEC) — National Electrical Code
- NEC Article 310 — Conductors for General Wiring (wire ampacity tables)
- NEC Chapter 9 Table 1 — Percent of Cross Section of Conduit for Conductors
- NEC Chapter 9 Table 4 — Dimensions and Percent Area of Conduit
- NEC Chapter 9 Table 5 — Dimensions of Insulated Conductors
Used for: conduit fill calculations, wire sizing, voltage drop formulas, ampacity references
Roofing
- NRCA Roofing Manual — National Roofing Contractors Association
- ASTM D3462 — Standard Specification for Asphalt Shingles
- ICC IRC Section R905 — Roof Covering requirements
Used for: shingle coverage (1 square = 100 ft²), bundle counts, waste factors, pitch-to-area conversions
General Construction
- ICC International Residential Code (IRC) — structural, framing, and foundation requirements
- ICC International Building Code (IBC) — commercial building requirements
- OSHA 29 CFR 1926 — Safety and Health Regulations for Construction
Used for: stud spacing, joist span, deck load requirements, general framing references
Manufacturer Technical Data
We reference manufacturer-published technical data sheets (TDS) for product-specific values:
- Quikrete, Sakrete — Concrete bag yields, coverage per bag, cure times
- CertainTeed, GAF, Owens Corning — Shingle coverage, bundle counts, exposure specifications
- Sherwin-Williams, Behr, Benjamin Moore — Paint coverage rates by product and finish
- Southwire, Cerro Wire — Wire gauge dimensions, resistance values, ampacity ratings
- USG, National Gypsum — Drywall joint compound coverage, screw spacing
Manufacturer values are used to set realistic defaults but may vary by product line, batch, and region. Users should verify with their supplier’s current specifications.
Trade Associations and Industry Guides
- Portland Cement Association (PCA) — concrete placement and curing practices
- National Asphalt Pavement Association (NAPA) — HMA paving best practices
- American Wood Council (AWC) — lumber spans, sizes, and grading
- Tile Council of North America (TCNA) — tile installation standards
- Brick Industry Association (BIA) — brick sizes, mortar joint dimensions
Internal Reference Tables
We maintain and publish the following planning-value tables derived from the sources above. These are conservative estimates; always confirm with your supplier.
Typical Material Densities
| Material | Density (Imperial) | Density (Metric) | Notes |
| Hot-Mix Asphalt (compacted) | ~145 lb/ft³ | ~2,320 kg/m³ | Varies by mix design and aggregate |
| Concrete (fresh, normal weight) | ~145 lb/ft³ | ~2,320 kg/m³ | Varies by slump, air content |
| Crushed Gravel (loose) | ~95–120 lb/ft³ | ~1,520–1,920 kg/m³ | Varies by gradation, moisture |
| Sand (dry) | ~90–110 lb/ft³ | ~1,440–1,760 kg/m³ | Moisture significantly increases density |
| Topsoil (loose) | ~75–90 lb/ft³ | ~1,200–1,440 kg/m³ | Varies by organic content, moisture |
| Mulch (loose) | ~15–25 lb/ft³ | ~240–400 kg/m³ | Varies by type (wood, rubber, etc.) |
Concrete Bag Yields
| Bag Size | Approximate Yield | Bags per Cubic Yard |
| 40 lb (18 kg) | ~0.30 ft³ (~8.5 L) | ~90 bags |
| 50 lb (23 kg) | ~0.375 ft³ (~10.6 L) | ~72 bags |
| 60 lb (27 kg) | ~0.45 ft³ (~12.7 L) | ~60 bags |
| 80 lb (36 kg) | ~0.60 ft³ (~17 L) | ~45 bags |
Paint Coverage
| Product Type | Coverage per Gallon (per coat) | Notes |
| Interior latex (eggshell/satin) | ~350–400 ft² (~32–37 m²) | Smooth walls, one coat. Reduce for porous or textured surfaces. |
| Interior latex (flat/matte) | ~400–450 ft² (~37–42 m²) | Flat finishes typically cover more per coat. |
| Exterior latex | ~250–350 ft² (~23–32 m²) | Depends on surface texture, weather, and porosity. |
| Primer | ~300–400 ft² (~28–37 m²) | New drywall, stains, and color changes require primer. |
Citation Policy
- Each calculator page references the specific sources used for its formulas and defaults
- This Data Sources page serves as the centralized reference library
- Sources are reviewed at least annually or when user feedback identifies a discrepancy
- Users can report missing or outdated sources through our Contact page