Shape balanced rooms with accurate RT60 checks. Add surfaces, choose materials, and see totals instantly. Download tables, share reports, and tune your studio confidently.
Enter room dimensions, then describe surfaces and materials. Add a custom absorption coefficient if you have lab data. Use Add surface for complex rooms.
The calculator estimates reverberation time (RT60) by octave band using equivalent absorption area A = Σ(area × α), where α is the absorption coefficient.
V is room volume (m³) and S is total surface area (m²). Use Eyring when average absorption is high.
Example inputs for a small control room. Replace coefficients with product test data when available.
| Item | Value | Notes |
|---|---|---|
| Room size | 6 m × 4 m × 2.7 m | Volume ≈ 64.8 m³ |
| Floor | 24 m², Carpet on pad | Higher absorption above 250 Hz |
| Ceiling | 24 m², Acoustic tile | Common mid/high control |
| Walls | 54 m², Painted gypsum board | Mostly reflective without treatment |
| People | 1 person, 0.35 m² sabins | Simple allowance |
| Typical mid RT60 | ~0.34 s | Often suitable for mixing rooms |
RT60 is the time required for sound to decay by 60 dB after the source stops. In studio design, RT60 is a practical indicator of perceived “liveness” and speech or mix clarity. Shorter times improve articulation and reduce masking, while longer times can add ambience but may blur detail. This calculator estimates RT60 across octave bands to highlight frequency-dependent behavior.
Accuracy depends on realistic geometry and reliable absorption coefficients. Start with correct room dimensions, then enter surface areas for floor, ceiling, untreated walls, and any added treatments. Use measured product coefficients when possible, because mounting methods, air gaps, and thickness can change performance. When you only have a single coefficient, the custom α override offers a conservative, simplified approach.
Sabine works well when average absorption is low to moderate, which often matches lightly treated spaces. As treatment increases, Sabine can predict unrealistically low times. Eyring accounts for the logarithmic behavior of high absorption and is generally more stable in highly treated control rooms and vocal booths. Comparing both methods helps you understand sensitivity before committing to materials.
A single “average RT60” can hide problems. Review the octave bands to spot boominess (longer low-frequency decay) or harshness (uneven mid or high decay). For many studio tasks, the 500–1000 Hz mid-band average is a useful reference, but treatment decisions should respond to the full band table. Use the target indicator as a quick check, not a final specification.
If mid-band RT60 is too long, increase absorption area using panels, thicker ceiling systems, or curtains in strategic zones. If RT60 is too short, reduce excessive absorption, add reflective surfaces, or introduce diffusion to maintain energy without long echoes. Long low-frequency RT60 usually requires bass traps or deeper porous absorbers. Export the CSV/PDF to track iterations and document design assumptions.
Many small control rooms aim around 0.20–0.50 seconds in the mid bands, depending on workflow and monitoring. Use your preferred standard and verify by measurement once treatments and furniture are installed.
Common finishes absorb little below 250 Hz, so bass energy persists. Address it with bass traps, thicker porous absorbers, tuned resonant devices, and careful placement. Geometry and modal behavior also influence perceived low-frequency decay.
Use Eyring when average absorption is high, such as vocal booths or control rooms with substantial treatment. It typically avoids overly optimistic short RT60 predictions. Sabine can still be useful for comparison and sensitivity checks.
Compute total wall area as 2(L×H + W×H). Then split that value into separate entries if different wall sections use different materials or treatments. Keep areas consistent with your selected unit system.
The override replaces the preset coefficients for that surface and applies one value to all octave bands. It is helpful when only a single absorption coefficient is available, but it may hide frequency-dependent behavior.
People and soft furnishings add absorption, especially in mid and high frequencies. Use the people allowance as a simple estimate, and add separate surface rows for large couches, thick curtains, or carpeted platforms when their areas are significant.
It is a design estimate, not a certification. Final acceptance should include on-site RT measurements and listening tests. Use this tool to compare options, document assumptions, and guide treatment planning before commissioning.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.