Rectangular Room Mode Calculator
List ideal axial, tangential and oblique resonance frequencies for a rectangular room.
YOUR CALCULATION
Result
—
Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Evaluate all nonzero integer mode-index triples within the entered bounds, classify by number of nonzero indices and sort by frequency.
f=(c/2)√[(nx/L)²+(ny/W)²+(nz/H)²]
Worked example
With sound speed 343 m/s and room length 5 m, the (1,0,0) axial mode is 34.3 Hz. A 2.5 m height gives (0,0,1) at 68.6 Hz.
Assumptions and input details
Ideal rigid, parallel rectangular boundaries and constant entered sound speed. Modes sharing a frequency remain separate degenerate modes. Index and frequency bounds limit the search; first 100 matching modes are listed with any omission count. No modal amplitude, damping, treatment efficacy or measured response is predicted.
References: MIT: room acoustics and modes
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Choose from 23 length definitions, including explicitly labelled regional measures. Area conversions square the length factor; geometric volumes cube it.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
NIST measurement tables · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
Estimate Sabine reverberation time and the replacement surface area needed for an entered target decay time.
Calculate wave speed, frequency or wavelength from the other two. Convert units, find the period and view an illustrative normalized wave.
Compare two propagation paths and entered electronic latency, then find the delay needed to align arrivals.
Reserved advertising space.