Acoustic Panel Calculator

Example Data Table

Sample scenarios to sanity-check typical outputs.

Formula Used

This calculator estimates the absorption required to reach a target reverberation time.

• Room volume: V = L × W × H
• Total surface area: S = 2(LW + LH + WH)
• Existing absorption: A₀ = S × α_avg
• Sabine requirement: A_req = K × V / RT60
• Additional absorption: A_add = max(0, A_req − A₀)
• Effective panel NRC: NRC_eff = NRC × (air gap factor) × (coverage efficiency)
• Absorption per panel: A_panel = (panel area) × NRC_eff
• Panels: N = ceil((A_add/A_panel) × (1+safety) × (1+waste))

K = 0.161 for metric units, and 0.049 for imperial units.

How to Use This Calculator

1. Select your units and enter the room length, width, and height.
2. Set a target RT60 based on room function and expectations.
3. Estimate existing average absorption using finishes and furnishings.
4. Enter panel size and NRC from the chosen product datasheet.
5. Adjust air gap factor and coverage efficiency for mounting details.
6. Add safety and waste percentages to match project risk tolerance.
7. Optionally include unit costs to estimate material and labor totals.
8. Press calculate, then export CSV or PDF for documentation.

Professional Guidance Article

1) What acoustic panels solve on site

Construction teams often complete interiors that look perfect but feel loud. Hard finishes reflect sound, raising reverberation and making speech tiring. Acoustic panels add absorption, reducing reflected energy and improving clarity in offices, classrooms, clinics, studios, and reception areas.

2) Why RT60 is a practical target

RT60 is the time needed for sound to decay by 60 dB after the source stops. Shorter RT60 usually means better intelligibility and less echo. A typical goal is 0.5–0.9 seconds for speech-focused rooms, while larger halls may accept longer values.

3) How the calculator estimates required absorption

The calculator uses the Sabine model to estimate the total absorption area required for a chosen RT60. It subtracts an estimate of existing absorption from finishes and furnishings, then converts the remaining absorption demand into a panel count based on panel size and effective NRC.

4) Choosing realistic existing absorption

If your space has carpet, curtains, upholstered seating, or bookcases, average absorption can be noticeably higher than a bare hard-surface room. Use conservative values when uncertain. Underestimating existing absorption slightly is safer than overestimating it.

5) NRC, air gaps, and placement effects

NRC is a simplified rating that represents mid-frequency absorption. Mounting panels with a standoff air gap can improve performance, especially at lower frequencies. Coverage efficiency captures practical losses from uneven distribution, partial obstructions, or installing only on one wall.

6) Cost and procurement planning

Budgets typically include panel material, fixings, and labor. Add waste for spares and handling damage. A safety factor helps account for unknowns like future furniture changes, open doors, or sound masking systems. Exported reports support approvals and subcontractor coordination.

7) Worked example with data

Example inputs: 10×7×3 m room, target RT60 = 0.8 s, average α = 0.10, 0.6×1.2 m panels, NRC = 0.85, air gap factor = 1.10, coverage efficiency = 0.95, safety = 10%, waste = 5%.

Example outcome: the model typically indicates a mid‑teens panel count for this scenario, with coverage well below total surface area. Adjusting the RT60 target or the assumed α can move the count significantly, so validate inputs with finish schedules.

8) Field notes for better results

Distribute panels across multiple surfaces rather than clustering them. Treat first reflection zones for workstations and meeting areas. If low-frequency control is important, consider thicker products, larger air gaps, or complementary absorbers. Always confirm fire rating, durability, and cleaning needs.

FAQs

1) Is this calculator suitable for every room?

It is a planning tool based on Sabine assumptions. It works best for typical enclosed rooms with fairly diffuse sound fields. Highly irregular spaces, very large volumes, or strong low‑frequency issues may need specialist modeling.

2) What if my existing absorption is unknown?

Start with a conservative low value and run a sensitivity check by trying a slightly higher value. Compare results with similar completed rooms, finish schedules, and furnishing plans to refine α before procurement.

3) Why can NRC be greater than 1.0?

Some products or mounting conditions can show absorption above unity in specific bands due to test setups and edge effects. The calculator accepts values above 1.0 to accommodate manufacturer data and air-gap improvements.

4) How should I set the air gap factor?

Use 1.0 for flush mounting. Use 1.05–1.25 for modest standoffs that improve performance. If you have lab data for the exact mounting depth, match the factor to that documented condition.

5) What does coverage efficiency represent?

It reduces ideal absorption to reflect real placement. Panels behind shelves, uneven spacing, or treating only one surface can reduce overall benefit. Use 0.85–0.95 for typical projects and closer to 1.0 for optimized layouts.

6) Should I treat the ceiling or the walls?

Either can work. Ceilings often provide uniform coverage and avoid damage risk, while wall panels help control reflections near listeners. Many successful designs combine both for balanced performance and aesthetics.

7) Do I still need testing after installation?

Yes, if performance is critical. A simple post‑fit RT60 measurement validates assumptions and supports handover documentation. If targets are missed, incremental panels or better distribution usually corrects the issue.