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Acoustic Laminated Glass STC Rating Estimator

Estimate an approximate STC (Sound Transmission Class) rating for a laminated/insulated glass makeup, from pane mass and interlayer/gap bonus.

Computed in your browser — nothing you enter is uploaded. Figures are presented for United States against IRC 2024, and every formula is cited under regulatory standards below.

Last verified 2026-08-27 · v1.1.0

Market
Imperial · sales tax

Estimated STC rating

35.56 STC (estimated)

Low confidence

This is an engineering rule-of-thumb estimate ONLY, not a certified rating — it ignores the coincidence-effect dip, frequency-dependent interlayer behavior, and installation effects. Always specify and verify acoustic performance using the manufacturer's actual ASTM E90 lab-tested STC value for your exact assembly, never this estimate, for any acoustic-critical project.

For the dimensions entered, expect a estimated stc rating of 35.6 STC (estimated). The confidence rating here is low. Get the figure confirmed by a supplier or a qualified trade before committing to it. Set for United States against IRC 2024. The market selector changes both the units and the code cited.

Add the equipment this sizes

This result is a specification — 35.564 STC (estimated) — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.

Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — confirmed fixes become pinned regression tests.

[Schema Verified] Computed in alignment with American Concrete Institute (ACI 318-19) formulas and International Residential Code (IRC 2024) spatial boundaries.

Regulatory standards & verification citations

  • Mass-law-based estimation rule of thumb: STC ≈ 13.5×log10(M1+M2) + 13 + R1, where M1/M2 are pane surface densities (kg/m²) and R1 is an empirical bonus for the interlayer/air-gap configuration — this is a widely-used industry estimation formula, NOT an ASTM E90-standardized predictive method

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Frequently asked questions

How accurate is this STC estimate?
Treat it as a rough rule-of-thumb only, not a certified value. It is a mass-law-based industry estimation formula, not an ASTM E90-standardized predictive method, and it ignores the coincidence-effect dip, frequency-dependent interlayer behavior, and installation effects that all influence a real assembly's measured STC.
Can I use this number in a project specification or acoustic compliance submittal?
No — for any acoustic-critical project, specify and verify performance using the manufacturer's actual ASTM E90 lab-tested STC rating for your exact glass makeup, not this estimate.
Where does the interlayer/gap bonus (R1) value come from?
It's an empirical adjustment for how much the interlayer or air/gas gap configuration improves on simple mass-law behavior — pull it from manufacturer data or published assembly comparisons for your specific makeup rather than assuming a default.