Tools & calculators
Calculators that turn room confusion into a plan.
Each tool here answers one room question the right way: live update, no sign-up, every formula and reference cited. We add a new one when an existing article would benefit more from doing the math than from reading another paragraph about it.
Use them in this order
- Score the room shape first. The room-mode calculator answers “is the shape any good?” — the only question whose answer you can’t fix later with absorption.
- Estimate the decay. The RT60 estimator answers “how much absorption do I need?” — the question that decides how many panels to buy.
- Pick the right inventory. Use the panel coverage calculator to convert m² of needed absorption into a specific shopping list.
Calculator · standing waves
Room-mode calculator
Find every standing-wave frequency below 300 Hz, score your room shape against Bolt / Louden / Sepmeyer references, and flag bass nulls before you commit to a single trap.
- Axial, tangential & oblique modes (order ≤ 4)
- Bolt-area plot, Bonello 1/3-octave density
- Schroeder frequency, plain-English commentary
Calculator · reverberation
RT60 estimator
Estimate how long sound lingers across six octave bands. Sabine + Eyring with editorial commentary on which numbers to trust — and which the room geometry won’t let you trust.
- 125 Hz – 4 kHz, six bands
- 20+ material library with cited α coefficients
- Schroeder-regime honesty in commentary
Calculator · panel coverage
Panel coverage calculator
Convert a target RT60 into a specific shopping list: m² of broadband absorption needed, split into wall panels, ceiling clouds, and corner traps — with cost-per-decay-second estimates.
- Pairs with the RT60 estimator
- Wall / ceiling / corner allocation
- Recommended product categories (no specific brands)
Calculator · transmission loss
Soundproofing (STC) estimator
Estimate the STC of a wall, door, or window assembly. Lab-sourced presets, decoupling modifiers, ASTM E413 contour visualization — with honest commentary on STC’s bass-leakage and flanking-path blind spots.
- NRC IRC-IR-693 + USG SA-100 lab data
- Wall / door / window presets with modifier stacking cap
- Bass-frequency “blind zone” honesty built into the chart
Calculator · level math
Decibel calculator
Add, subtract, and compare sound levels the only mathematically sane way: logarithmically. Combine multiple sources, predict distance attenuation by source geometry, or compare any level against a 0–140 dB calibrated reference ladder.
- Logarithmic source combination (the +3 dB rule done right)
- Point / line / diffuse-field distance attenuation
- Reference ladder with OSHA & WHO thresholds
Why these specific five?
Every other “acoustic calculator” we’ve audited online either oversimplifies (one input, one number, no commentary) or sells you panels at the end. The set here covers the five actually independent decisions a reader makes about a room:
- Is the room shape any good? — Room-mode calculator. The answer determines whether treatment can even reach diminishing returns.
- How much treatment do I need? — RT60 estimator. The answer is in m² of absorption, by octave band.
- What products satisfy that? — Panel coverage calculator. The answer is a category-level shopping list.
- How much do I need to block sound going elsewhere? — Soundproofing (STC) estimator. Independent of the first three: this is soundproofing, not treatment.
- How do I combine sources / distances? — Decibel calculator. The math primitive that underlies all four; we publish it on its own so every article that uses dB arithmetic can link to it.
If a calculator you wish existed isn’t here, tell us. The build queue is shaped by reader requests, not by what’s easiest to monetize.