TryBuildCalcSoundproofing Calculator (STC Rating & Acoustic Drywall Materials)
Estimate a wall's STC rating and the resilient channel, Green Glue, and MLV materials needed.
🕒 Last updated: October 10, 2026
Inputs
Section 1: Wall Dimensions
ℹ️Set to more than 1 if several identical walls need the same acoustic treatment (e.g. all walls of a studio).
Section 2: Framing
One row of studs shared by both wall faces — the most common residential/commercial wall.
ℹ️Mainly affects resilient-channel screw count in this calculator — spacing alone does not meaningfully change the STC rating at typical residential spacings.
Section 3: Layers & Acoustic Treatments
Use the Drywall Sheet Calculator for the exact sheet count/packing for this many layers — this calculator only estimates the STC impact and the acoustic-specific add-on materials below.
Use the Batt & Roll Insulation Calculator for the exact batt count for this wall.
One side only, 24 in o.c. — the single biggest easy upgrade on a single-stud wall, but installation-sensitive: a single screw driven through into the stud behind it "shorts out" the decoupling.
Green Glue requires 2 drywall layers per side — select "2 Layers" above to enable it.
A modest, flat contribution on its own (MLV's own standalone STC is only about 20-31) — most effective layered with other treatments, not as a standalone strategy.
Section 4: Cost
Estimated STC 33 (Below Average)
For 1 wall(s), 8.92 m² total.
Sound Rating
Estimated STC Rating: 33 (typical range 30-36)
Performance Category: Below Average — Normal speech is clearly audible and easily understood through the wall.
Acoustic Materials
No add-on acoustic materials selected — this assembly's rating comes from framing and layers alone.
Quick Insight
Estimated STC 33 (typical range 30-36) for a single-stud wood wall with 1 drywall layer per side — rated "Below Average".
Approximate results for planning only. Verify with a professional.
Wall Assembly Cross-Section
What Is a Soundproofing Calculator?
If you're asking "how do I soundproof a wall" or "what STC rating will this wall actually get," this calculator answers it from the real framing, drywall layer, and acoustic treatment choices you'd actually build with. It returns an estimated STC (Sound Transmission Class) rating with a realistic range and performance category, plus the resilient channel, Green Glue damping compound, and mass-loaded vinyl (MLV) quantities and cost for whichever add-on treatments you select.
It is built for homeowners soundproofing a home theater, office, or shared wall, and for contractors pricing an acoustic upgrade, as a companion to the Drywall Sheet Calculator (base sheet count) and the Batt & Roll Insulation Calculator (cavity insulation quantity), which this calculator deliberately does not re-derive.
What makes this calculator different:
STC is a lab-tested rating, not a value a formula can cleanly derive from its parts — so most online soundproofing tools either give a vague qualitative answer or quote a single suspiciously precise number. This calculator instead anchors to specific, named, independently cross-verified tested assemblies (stcratings.com's assembly table, commercial-acoustics.com's single/staggered/double-stud guides, and Green Glue's own published application data), fills in the untested combinations between those anchors the same disclosed-approximation way this site's R-Value Calculator handles its steel-framing correction, and reports a realistic range rather than false precision.
Applicable standards:
- STC is defined and measured per ASTM E90 (laboratory test method) and ASTM E413 (classification/rating method).
- The Gypsum Association's GA-600 Fire Resistance and Sound Control Design Manual is the North American industry reference for published tested assemblies — consult it directly for a code submittal or contractual guarantee.
- This calculator estimates STC and acoustic material quantity/cost only, not an acoustic consultant's field test or a code compliance determination.
How the soundproofing calculation works
The STC estimate is built from named, cited tested-assembly anchor points plus documented deltas for each add-on — not a single additive formula, since STC genuinely does not add up that way in real tested data.
Step 1 - Start from the base assembly
Single/Wood, 1 layer, uninsulated = STC 33
Single/Wood, 1 layer, insulated = STC 37
Single/Steel, 1 layer, uninsulated = STC 39
Single/Steel, 1 layer, insulated = STC 44
Staggered/Wood, insulated (always) = STC 47
Double/Wood, insulated (always) = STC 60
These are anchor points cross-verified across multiple independent published sources, not a derived formula result.
Step 2 - Add a 2nd drywall layer per side, if selected
Single/Wood +7, Single/Steel +6, Staggered +6, Double +4
Smaller deltas on staggered/double-stud walls reflect a real, documented diminishing return — decoupling has already captured most of the achievable benefit before a 2nd layer is added.
Step 3 - Add resilient channel, Green Glue, and/or MLV, if selected
Resilient Channel (Single/Wood only) = +11
Green Glue, One Side = +8 (Single), +5 (Staggered), +2 (Double)
Green Glue, Both Sides = +12 (Single), +9 (Staggered), +3 (Double)
MLV add-on = +2 (flat, any assembly)
Resilient channel is only modeled on single wood-stud walls — the primary documented use case. Green Glue requires 2 drywall layers per side.
Step 4 - Report a realistic range, not a bare number
Typical range = Estimate ± 3 (± 5 if resilient channel is used)
A wider range is used whenever resilient channel is part of the assembly, since sources explicitly flag it as especially installation-sensitive.
Step 5 - Resilient channel, Green Glue, and MLV materials
RC Runs per Wall = CEIL(Wall Height / 2 ft) + 1, at 24 in o.c.
If Wall Width <= 12 ft: RC Pieces = CEIL(Total Runs / FLOOR(12 ft / Wall Width))
If Wall Width > 12 ft: RC Pieces = CEIL(Wall Width / 12 ft) x Total Runs
Green Glue Tubes = CEIL((Wall Area x Interfaces x 10.7639) / 16 sq ft per tube)
MLV Rolls = CEIL((Wall Area x 1.1) / 100 sq ft per roll)
Resilient channel is cut to length on site (unlike corner bead, which must run one continuous piece per physical corner), so runs shorter than the 12 ft stock length are packed multiple-per-piece rather than each getting its own dedicated piece — a wall wider than 12 ft still needs 2+ pieces for every single run, since no other run can share a piece that large.
Real-World Soundproofing Calculation Example
This example uses the active calculator inputs above and follows the same steps from the formula section.
Input Values Used
| Input | Value | Why it is used |
|---|---|---|
| Framing | Single Stud Wall, Wood | Sets the base STC anchor point |
| Drywall Layers | 1 per side | Adds the 2nd-layer delta if 2 |
| Insulation | No | Selects the insulated vs. uninsulated base anchor |
| Treatments | None | Adds each selected delta |
Step 1 — STC Breakdown
| Step | Delta | Running Total |
|---|---|---|
| Base: single-stud wood framing, 1 layer/side, uninsulated | 33 | 33 |
Step 2 — Acoustic Materials
| Material | Calculation | Result |
|---|---|---|
| No add-on acoustic materials selected. | ||
Therefore, for this wall you can expect an estimated STC 33 (typical range 30-36), rated "Below Average".
Essential Checklist+−
Complete these critical checks before approving the work or proceeding to the next construction stage.
✓Wall & Framing Setup+-
- Wall width, height, and the number of identical walls were measured on site, not assumed from a floor plan.
- Framing Type (single/staggered/double stud) matches what is actually being built or already exists in the wall.
- Wall width and height were entered in consistent units — both feet or both metres, not mixed.
✓Layers & Insulation+-
- Drywall Layers per Side (1 or 2) matches the actual installation plan for BOTH wall faces equally — this calculator assumes a symmetric assembly.
✓Acoustic Add-On Treatments+-
- Resilient channel installation plan explicitly avoids any screw long enough to reach the stud through the channel — a single "shorted" screw measurably degrades real-world performance below the lab-tested number.
✓Materials Takeoff & Cost+-
- Resilient channel piece count accounts for every wall wider than one 12 ft stock length needing 2+ pieces PER horizontal run, not one combined total divided by 12 ft.
- Acoustic materials cost total is understood as scoped ONLY to resilient channel, Green Glue, and MLV — not a whole-wall materials cost (drywall sheets, studs, insulation batts, and finishing compound are priced separately via their own calculators).
✓Interpreting the Result+-
- The estimated STC and its stated range are understood as a PLANNING estimate for comparing options, not a lab-certified rating for a code submittal or contractual guarantee.
- If a specific STC rating is contractually required (e.g. a multi-family code minimum), a genuine GA-600 or manufacturer-published tested assembly matching the actual construction was independently confirmed.
Full QC Checklist+−
Verify wall setup, layer/insulation selection, acoustic treatment installation, materials takeoff, and result interpretation before relying on the estimated STC rating.
✓Wall & Framing Setup+-
- Wall width, height, and the number of identical walls were measured on site, not assumed from a floor plan.
- Framing Type (single/staggered/double stud) matches what is actually being built or already exists in the wall.
- Framing Material (wood/steel) and Stud Spacing match the real framing — steel-vs-wood changes the baseline STC meaningfully.
- If a double or staggered stud wall, the plates are genuinely separate (double) or alternated on one shared plate (staggered) as modeled — a wall that doesn't match either pattern should use Single Stud instead.
- Wall width and height were entered in consistent units — both feet or both metres, not mixed.
✓Layers & Insulation+-
- Drywall Layers per Side (1 or 2) matches the actual installation plan for BOTH wall faces equally — this calculator assumes a symmetric assembly.
- Cavity Insulation selection matches whether batt insulation is actually installed — staggered/double-stud walls are always modeled as insulated since an uninsulated version is not a realistic build.
- The exact batt/roll quantity for the selected insulation is cross-checked against the Batt & Roll Insulation Calculator, not estimated here.
✓Acoustic Add-On Treatments+-
- Resilient channel (if used) is confirmed available only for single wood-stud walls — the combination is silently ignored on steel, staggered, or double-stud framing, which this calculator does not model (published test data exists for steel-stud resilient channel; it is simply out of this calculator's current scope).
- Resilient channel installation plan explicitly avoids any screw long enough to reach the stud through the channel — a single "shorted" screw measurably degrades real-world performance below the lab-tested number.
- Green Glue (if used) is confirmed available only when 2 drywall layers per side are selected — it bonds the two layers together, it does not replace a layer.
- Green Glue is applied at the manufacturer's stated rate (2 tubes per 4x8 ft sheet / 32 sq ft) in a bead pattern per the product's own instructions, not spread thin to stretch coverage.
- MLV (if used) is installed with all seams taped and no gaps or tears — a torn or gapped MLV sheet loses most of its mass-barrier benefit at that point.
✓Materials Takeoff & Cost+-
- Resilient channel piece count accounts for every wall wider than one 12 ft stock length needing 2+ pieces PER horizontal run, not one combined total divided by 12 ft.
- Resilient channel run spacing (24 in o.c. max) and screw count match the stud spacing actually used.
- Green Glue tube count and MLV roll count were rounded UP to whole units, with a wastage allowance considered for cut-offs and corners.
- Acoustic materials cost total is understood as scoped ONLY to resilient channel, Green Glue, and MLV — not a whole-wall materials cost (drywall sheets, studs, insulation batts, and finishing compound are priced separately via their own calculators).
- Currency and unit cost entries reflect current local supplier pricing, not a default placeholder.
✓Interpreting the Result+-
- The estimated STC and its stated range are understood as a PLANNING estimate for comparing options, not a lab-certified rating for a code submittal or contractual guarantee.
- If a specific STC rating is contractually required (e.g. a multi-family code minimum), a genuine GA-600 or manufacturer-published tested assembly matching the actual construction was independently confirmed.
- The performance category description (what can realistically be heard through the wall) was communicated to the client/occupant in plain terms, not just the bare STC number.
Reference Tables
STC rating speech-privacy scale (general rule of thumb)
| STC Range | Category | What can be heard |
|---|---|---|
| Below 35 | Below Average | Normal speech is clearly audible and easily understood |
| 35-39 | Fair | Loud speech audible and partly understood; normal speech faintly heard |
| 40-44 | Good | Loud speech audible but mostly unintelligible; normal speech barely heard |
| 45-49 | Very Good | Must strain to hear loud speech; normal conversation essentially inaudible |
| 50-59 | Excellent | Loud speech/most TV barely audible — common multi-family code minimum |
| 60+ | Superior | Suitable for home theaters/studios; only very loud sound faintly perceptible |
Base assembly anchor points (1 layer per side)
| Framing | Insulation | STC |
|---|---|---|
| Single Stud, Wood | Uninsulated | 33 |
| Single Stud, Wood | Insulated | 37 |
| Single Stud, Steel | Uninsulated | 39 |
| Single Stud, Steel | Insulated | 44 |
| Staggered Stud, Wood | Insulated (always) | 47 |
| Double Stud, Wood | Insulated (always) | 60 |
Acoustic treatment materials coverage
| Material | Coverage / Stock Size | Source |
|---|---|---|
| Resilient Channel | 12 ft stock length, 24 in o.c. max spacing | ClarkDietrich installation guidelines |
| Green Glue Noiseproofing Compound | 16 sq ft per 28 oz tube (2 tubes per 4x8 ft sheet) | Green Glue's own published standard application rate |
| Mass-Loaded Vinyl (MLV) | 100 sq ft per roll (4 ft x 25 ft) | Common retail MLV roll size |
Confirm exact coverage and spacing against the specific product's own technical data sheet before finalizing an order — these figures are general planning guidance only.
How to Use the Soundproofing Calculator
- Enter the wall's width and height, and how many identical walls need the same treatment.
- Pick a Framing Type — Single Stud for most residential/commercial walls, Staggered or Double Stud if you are building new and want the best wood-frame isolation available.
- For a single-stud wall, choose Wood or Steel framing — steel changes the baseline rating meaningfully even before any add-on treatment.
- Choose 1 or 2 drywall layers per side, and whether cavity insulation is installed (forced on for staggered/double-stud walls, since that is how they are actually built).
- Add Resilient Channel, Green Glue, and/or MLV as needed, then enable cost estimation to price just those acoustic-specific materials.
Practical Soundproofing Tips
- Seal the perimeter gap between drywall and the framing/floor/ceiling with acoustical sealant — an untreated gap is a direct air path that can undo much of an otherwise well-built assembly's rated performance.
- Never let a resilient-channel screw reach the stud behind the channel — use the manufacturer's specified screw length, and check a sample screw depth before fastening the whole wall.
- Stop electrical boxes, outlets, and recessed fixtures from lining up back-to-back on opposite sides of the same stud bay — a shared penetration is a common, easily avoidable flanking-noise path.
- If budget only allows one upgrade on a single-stud wall, resilient channel or a 2nd Green Glue-bonded layer each deliver a bigger jump than most other single changes for the cost.
- Low-frequency sound (bass, footsteps, machinery) is the hardest to block and benefits most from mass and air-gap width — a double-stud wall or added MLV helps more there than a thin treatment alone.
Common Mistakes
- Treating a quoted STC number as a guarantee rather than a lab-tested figure that real-world installation quality can significantly move.
- Driving resilient-channel screws long enough to reach the stud behind it, silently shorting out the entire decoupling benefit.
- Adding mass (extra drywall, MLV) without also addressing decoupling or damping, then being surprised the improvement is smaller than expected — mass alone has real but limited returns.
- Leaving an unsealed gap anywhere around the wall's perimeter, at outlet boxes, or at duct penetrations, undoing much of the assembly's rated performance through a simple air path.
- Assuming a staggered or double-stud wall's published rating applies without cavity insulation — virtually all published data for those assemblies assumes insulation is present.
- Using Green Glue on only 1 drywall layer per side, where it has nothing to bond between and does nothing.
Soundproofing Calculator Limitations
- This calculator provides a planning estimate only and does not replace a genuine GA-600 or manufacturer-published lab-tested assembly for a code submittal or contractual guarantee.
- STC is not a value a formula can derive precisely from its parts — the base anchor points and deltas used here are cross-verified against multiple independent published sources, with untested combinations interpolated and disclosed as such, not transcribed cell-by-cell from a single authoritative table.
- Real-world performance depends heavily on installation quality (sealing, screw placement, consistent insulation fill) in ways this calculator cannot verify from inputs alone.
- Only wall assemblies are modeled — floor/ceiling impact noise (IIC rating, footstep/impact sound between stories) is a genuinely different rating system and construction, not covered here.
- Resilient channel is only modeled on single wood-stud walls; Green Glue one-side-on-a-double-stud-wall is the least certain delta in the table (a less commonly tested combination) — both are disclosed in the Formula section.
- Base drywall sheet count, cavity insulation quantity, and joint finishing materials are not estimated here — see the Drywall Sheet, Batt & Roll Insulation, and Drywall Mud/Tape Calculators for those.
- This calculator assumes a symmetric wall (the same layer count on both faces) and does not model flanking-noise paths (shared ductwork, electrical boxes, structural connections) separately.
Related Construction Calculators
You may also find these calculators useful for the same wall:
- Drywall Sheet Calculator
Estimate the exact sheet count and screws for this wall's drywall layers.
- Batt & Roll Insulation Calculator
Estimate the exact batt/roll count for this wall's cavity insulation.
- Drywall Mud Calculator
Estimate joint compound and tape once the layers are hung.
- R-Value Calculator
Check this same wall's thermal R-value and U-factor.
Disclaimer: This calculator provides approximate results for planning and estimation purposes only. Actual requirements may vary based on site conditions, materials, workmanship, and local building regulations. Always consult a qualified engineer, architect, or construction professional before making final decisions.