Quick RT60 Calculator

Calculate reverberation time in 30 seconds. Enter room volume, select a surface material, and get instant RT60 with compliance check.

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Reverberation Time (RT60)

The time in seconds for sound pressure level in a room to decay by 60 dB after a sound source stops. RT60 is the single most important metric in architectural acoustics, used by every major compliance framework including WELL v2, BB93, ANSI S12.60, and DIN 18041.

Reference: ISO 3382-2:2008

How the Quick Calculator Works

Enter Dimensions

Length, width, height in metres. Volume and surface area calculated automatically.

Select Material

Choose dominant surface from 5,600+ materials. Absorption coefficient applied automatically.

Get RT60

Instant RT60 prediction with compliance check against your selected standard.

RT60 Targets by Room Type

Room Type	Target RT60	Standard
Classroom	0.4 – 0.6s	ANSI S12.60 / BB93
Open-plan office	0.5 – 0.8s	BS 8233 / WELL v2
Meeting room	0.4 – 0.6s	DIN 18041 Group A
Recording studio	0.2 – 0.4s	EBU Tech 3276
Concert hall	1.5 – 2.2s	ISO 3382-1
Restaurant	0.6 – 1.0s	BS 8233:2014
Hospital ward	0.5 – 0.8s	HTM 08-01
Home studio	0.3 – 0.5s	Industry standard

Quick Calculator vs Full Calculator

Quick Calculator

✓ Feasibility studies
✓ Preliminary design estimates
✓ Client presentations
✓ Quick compliance pre-check
✓ Educational purposes

Full Calculator

✓ Octave-band RT60 (125\u20134000 Hz)
✓ Per-surface material assignment
✓ STI / speech intelligibility
✓ WELL / LEED compliance reports
✓ AI-powered auto-solve
✓ PDF/DOCX report generation

The Formula Behind the Calculator

The quick calculator uses Sabine's equation (ISO 3382-2:2008 Annex A.1):

T₆₀ = 0.161 × V / A

Where:

V = room volume (m³)
A = total absorption (m² Sabine) = Σ(α_i × S_i)
α_i = absorption coefficient of surface i
S_i = area of surface i (m²)

For rooms with average absorption above 0.3, the full calculator automatically switches to Eyring's formula for improved accuracy. Learn more about Sabine vs Eyring.

Frequently Asked Questions

How accurate is a quick RT60 calculation?▾

A simplified RT60 calculation using room volume and average absorption coefficient is typically accurate to within 15-20% for rooms with relatively uniform surface treatment. For detailed design, use the full calculator which models each surface independently with octave-band absorption coefficients. The quick method uses Sabine's equation (T60 = 0.161V/A) which is appropriate for rooms with average absorption below 0.3.

What inputs do I need for a quick RT60 estimate?▾

For a quick estimate, you need three inputs: room volume in cubic metres (length × width × height), the dominant surface material (which determines the average absorption coefficient), and the room type (which determines the target RT60 from the applicable standard). The calculator uses Sabine's formula to predict RT60 and compares it against the target for your room type.

When should I use the full calculator instead?▾

Use the full calculator when: different surfaces have different materials (e.g., acoustic ceiling tiles but hard walls), when you need octave-band RT60 predictions (especially for low-frequency compliance), when average absorption exceeds 0.3 (Eyring's formula is more appropriate), or when you need to generate compliance reports for WELL, LEED, or building code submissions.

What RT60 should my room achieve?▾

Target RT60 depends on room function: classrooms 0.4-0.6s (ANSI S12.60), open-plan offices 0.5-0.8s (BS 8233), meeting rooms 0.4-0.6s (DIN 18041), recording studios 0.2-0.4s, concert halls 1.5-2.2s (ISO 3382-1), restaurants 0.6-1.0s. The calculator automatically applies the correct target based on your room type selection.

Ready to Calculate?

Open the free calculator to get instant RT60 predictions with compliance checking against international standards. No account required.

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