Free Sound Pressure Level Calculator

Calculate sound pressure level in decibels from RMS sound pressure using SPL = 20 * log10(p / p0).

Pa

Sound Pressure Level

94.0 dB SPL

Sound Pressure Level vs RMS Sound Pressure

Sound Pressure Level (SPL)

SPL quantifies the RMS sound pressure relative to the threshold of hearing on a logarithmic scale.

Formula

SPL = 20 * log10(p / p_0)

where p_0 = 20 micro-Pa = 2 x 10^-5 Pa is the reference pressure corresponding to the threshold of human hearing at 1 kHz.

Example Calculation

A sound wave with RMS pressure of 1 Pa.

  1. 01SPL = 20 * log10(p / p_0)
  2. 02SPL = 20 * log10(1 / 0.00002)
  3. 03SPL = 20 * log10(50000)
  4. 04SPL = 20 * 4.699 = 94.0 dB SPL

Frequently Asked Questions

Learn More

Understanding Newton's Laws of Motion

A comprehensive guide to Newton's three laws of motion. Learn about inertia, force and acceleration, action-reaction pairs, and how these principles govern everyday physics.

Related Calculators