STC Calculator

Use the STC Calculator to find the STC Rating of your wall by filling out the form below. Use our resources below to find more cost-effective ways to improve your STC Rating, or use the STC Calculator to determine alternate wall designs.



STC Resources

Common Wall STCs by Construction Type

Target STCs by Building Use

How to Improve STC Ratings in Your Wall

STC (Sound Transmission Classification) Overview

STC Ratings for Load-Bearing Walls

Common STC Ratings

International Building Code requires 50 STC between adjacent dwelling units. Although that’ll help you meet code, it doesn’t mean it’s sufficient to block out the noise tenants expect. There are a number of other building codes with stricter regulations, including the National Association of Home Builders, which requires an STC of 60. Target STCs for classrooms and traditional commercial space is 40-45, while doctor’s offices and DoD installations with HIPAA or classified information may require 55 or higher. 

Also, remember that Field STC Ratings (ASTC, or Apparent Sound Transmission Class) per ASTM E336 and Lab STC Ratings per ASTM E90 can vary depending on a number of factors. For instance, Resilient Channel requires a complex installation process and should be carefully monitored by a soundproofing consultant to ensure that it is not grounded by cabinets, shelving, televisions, or general grounding by faulty screws. Likewise, flanking paths develop along baseboards and through doors and windows. It is common for field- and lab-STC values to fluctuate by 5 points or more due to the several common flanking paths that are likely to develop.

Was the STC Calculator helpful? Contact us if you need lab-rated STC assemblies