Engineering disclaimer

SiteSpecCalc calculations are for estimation and planning. They are not a substitute for construction documents prepared or reviewed by a licensed professional engineer, a licensed electrician, or the local building official. Verify every quantity before you order, cut, or energize anything.

Concrete volume ignores waste you create in the field beyond the factor you select, and it ignores soil, frost, vapor, joints, and structural capacity. Rebar counts are an on-center takeoff, not an ACI development-length design. Bag yields are the common 0.60 and 0.45 cubic foot figures. Read the bag.

Voltage drop uses the approximate K method, not a project-specific impedance study. Ampacity is the 75°C column with the small-conductor limits and an optional 125 percent continuous factor. It does not apply correction factors, adjustment factors, or the utility's service rules. A dwelling service may be allowed a smaller conductor under NEC 310.12 where that section is adopted. The inspector decides.

Stair math divides the rise you type into equal risers and checks them against 7.75 inches and 4 inches, and treads against 10 inches. It does not check headroom, guards, handrails, landings, or the stair width required for the occupancy. Roof math returns geometry and a material count. It does not size a rafter for snow, wind, or span.

Code sections named on a page are signposts to the published model codes. The edition adopted in your jurisdiction, including local amendments, controls. SiteSpecCalc is not affiliated with NFPA, ICC, or ACI.