SiteCalc code references feature: calculators reference NEC 310.16 wire sizing tables, IRC R311.7 stair dimensions, IPC 704.1 drain fixture units, and IFGC gas pipe sizing tables. The code section is shown alongside each calculation result. Part of SiteCalc, a $29.99 iOS app by Creayo LLC.

The code section, not just the answer

SiteCalc doesn't just give you a wire size. It tells you that wire size comes from NEC Table 310.16, 75C column, copper conductors. You get the answer and the code reference so you can verify it yourself or show it to the inspector standing behind you.

NEC for electrical

Wire sizing pulls from NEC 310.16 ampacity tables. Conduit fill calculations reference NEC 314.16 for box fill and Chapter 9 tables for conduit. Voltage drop formulas use NEC-recommended maximums. The specific table and section are shown next to every electrical result.

When you're pulling wire for a 60-amp sub-panel 150 feet from the main, you want to know the code backs up the gauge you're buying.

IRC for residential building

Stair calculations reference IRC R311.7 for riser height, tread depth, headroom, and handrail requirements. Span tables pull from IRC Chapter 5. Header sizing follows IRC R602.7. The code section sits right next to the calculated value.

Useful when a homeowner asks why the stairs have to be a certain dimension. Point to the code.

IPC and IFGC for plumbing and gas

Drain slope calculations reference IPC 704.1. Fixture unit counts follow IPC Chapter 7 DFU tables. Gas pipe sizing pulls from IFGC tables based on BTU load, pipe length, and inlet pressure.

These aren't summaries of the code. They're direct references to the specific table or section that produces the number on your screen.

Reference, not certification

SiteCalc is a calculator, not a code compliance tool. The references help you look up the right section and understand where the math comes from. Local amendments, inspector interpretations, and job-specific conditions are still on you. Always check with your local authority having jurisdiction. The code references give you a starting point and a citation to work from.

Related features

  • Show Formula -- see the exact equation behind every calculation.
  • PDF Export -- code citations carry through to exported documents for inspectors.

Read more: How to Size Wire for a Circuit (NEC 310.16) | How to Size a Header (IRC R602.7) | Drain Pipe Sizing (IPC DFU Table)

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