About RoughIn

RoughIn is a set of free sizing calculators for HVAC, plumbing and electrical work. Each one does a single calculation well: it shows its inputs, its formula and its source, so you can check the result instead of trusting a black box.

How the numbers are checked

Tables are transcribed from the published code and compared with a second source. Every calculator is then run against the code's own worked results, such as NEC Annex C for conduit fill and the IFGC capacity tables for gas pipe, before it is published. Where sources disagree, the value is left out until it can be confirmed.

Corrections

If you find a result that disagrees with your code book, email [email protected] with the inputs and the table you compared against. Corrections are published with a note on the page.