● calcnet

Data licensing

Data Licensing & Attribution

Every dataset that powers a calculator is listed below with its source, license, and the attribution string we publish on the calculator's page. Where a publisher requires attribution (NREL, USDA), the string is shown verbatim. Where math is the only content used and is not copyrightable under Baker v. Selden, we say so explicitly.

  1. 1. ADA 2010 Standards for Accessible Design

    Used by
    ADA Ramp Slope Calculator
    Publisher
    US Department of Justice / US Access Board
    License
    Public domain (federal work, 17 U.S.C. § 105)
    Source URL
    https://www.ada.gov/law-and-regs/design-standards/2010-stds/
    Attribution string
    ADA 2010 Standards for Accessible Design (US Access Board, public domain).
    Date accessed
    2026-05-20

  2. 2. ACI 318 Development Length & Splice Formulas (math only)

    Used by
    Rebar Lap Splice Calculator
    Publisher
    American Concrete Institute
    License
    Formulas are not copyrightable per Baker v. Selden, 101 U.S. 99. ACI 318 table layouts are NOT reproduced; only the mathematical formulas are implemented.
    Source URL
    https://www.concrete.org/store/productdetail.aspx?ItemID=318U24
    Attribution string
    ACI 318 §25.4.2 + §25.5.2 simplified development length and lap splice formulas (mathematical content, not table layout).
    Date accessed
    2026-05-20

  3. 3. IECC Climate Zone Map + DOE per-square-foot loads

    Used by
    Room BTU Load Calculator
    Publisher
    US Department of Energy, Pacific Northwest National Laboratory
    License
    Public domain (federal work)
    Source URL
    https://basc.pnnl.gov/images/iecc-climate-zone-map
    Attribution string
    IECC Climate Zone Map and DOE Building America loads (PNNL, public domain). Method derived from ACCA Manual J shortcut procedure.
    Date accessed
    2026-05-21

  4. 4. Industry-standard waste percentages by pattern

    Used by
    Tile Waste & Pattern Calculator
    Publisher
    Compiled from public installer guidance (multiple sources)
    License
    Industry rules of thumb; no proprietary tables reproduced. TCNA Handbook method codes (F113, TR711, etc.) are NOT referenced.
    Source URL
    https://www.tcnatile.com/about-tcna
    Attribution string
    Waste percentages compiled from public installer guidance; verify against your tile vendor's recommended overage.
    Date accessed
    2026-05-21

  5. 5. USDA Plant Hardiness Zone Map + extension publications

    Used by
    Beekeeping Hive Expansion Calculator
    Publisher
    USDA Agricultural Research Service + state extension services (UF/IFAS, NCSU, OSU, UMaine)
    License
    Public domain (USDA, federal) + state extension publications (state-funded, freely usable)
    Source URL
    https://planthardiness.ars.usda.gov/
    Attribution string
    Decision logic synthesized from US beekeeping extension publications — UF/IFAS, NCSU, OSU, UMaine extension.
    Date accessed
    2026-05-21

  6. 6. Electrode deposit weights and efficiencies

    Used by
    Welding Rod Consumption Calculator
    Publisher
    Lincoln Electric + Miller Electric
    License
    Public manufacturer datasheets (freely available marketing materials)
    Source URL
    https://www.lincolnelectric.com/en/Knowledge-and-Resources
    Attribution string
    Deposit weights and efficiencies from Lincoln Electric and Miller Electric public datasheets. Steel density per AISC Steel Construction Manual.
    Date accessed
    2026-05-21

  7. 7. Salt mix and additive manufacturer specifications

    Used by
    Reef Tank Dosing Calculator
    Publisher
    Bulk Reef Supply + Red Sea + Tropic Marin + Aquaforest
    License
    Public manufacturer datasheets (marketing materials)
    Source URL
    https://www.bulkreefsupply.com/two-part-bulk
    Attribution string
    Brand specifications from Bulk Reef Supply, Red Sea, Tropic Marin, and Aquaforest public datasheets.
    Date accessed
    2026-05-21

  8. 8. National Solar Radiation Database (NSRDB), summarized by metro

    Used by
    Solar Panel Tilt Angle Calculator
    Publisher
    NREL — National Renewable Energy Laboratory
    License
    Public domain (federal work). NREL requests attribution as a courtesy.
    Source URL
    https://nsrdb.nrel.gov/
    Attribution string
    Monthly irradiance from NREL National Solar Radiation Database (NSRDB), summarized by metro. Tilt and azimuth formulas from Sandia PV Performance Modeling Collaborative.
    Date accessed
    2026-05-21

Why this page exists

Two reasons:

  1. Required attribution. NREL and USDA both request attribution as a condition of use of their public datasets. This page is the canonical place where calcnet acknowledges them.
  2. Reader transparency. A calculator is only as trustworthy as its sources. Showing every source means readers can verify the numbers against the originals — and notice if a dataset has updated since our last verification.

Quarterly refresh

Datasets are re-checked every quarter via the content-refresh skill in this repo. When a source changes, the "Date accessed" updates and the change is noted in the site's RSS feed.

Errata

If a published value here is wrong, or a source URL has moved, email [email protected] and we'll fix it within a week.