Sound Delay Calculator

Methodology

How it works

Use this calculator when you need a starting point for a delay setting, or want to understand how far sound travels during a known interval. Choose Distance → time for a single travel path, Time → distance for the reverse calculation, or Align two sources to compare two paths. Enter distances in meters or feet. Switching units converts the existing measurements instead of changing their physical meaning. An empty or out-of-range measurement clears the result until you correct it. The estimate uses c = 331.3 + 0.606 × T, where c is sound speed in meters per second and T is air temperature in degrees Celsius. At the default 20 °C, c is 343.42 m/s and a 10 m path takes about 29.119 ms. One foot is exactly 0.3048 m. Time in milliseconds is distance divided by c, multiplied by 1,000. The reverse calculation multiplies time in seconds by c. This is a practical temperature approximation for sound in air, supported here from −20 to 50 °C. The displayed precision describes the calculation, not the accuracy of your measurements. For two sources, measure source A and source B to the same listening point. The shorter path arrives first and is the source that receives the calculated additional delay. For example, with A at 20 m and B at 5 m, B needs about 43.678 ms of geometric delay at 20 °C. Equal paths need no geometric correction. Moving the listening point can change both the amount and which source arrives first. Do not substitute the distance between the speakers for these two path measurements. The calculation assumes both sources emit at the same time before the added delay. It does not include latency from consoles, DSP, wireless equipment or other devices, nor wind, humidity, room reflections or frequency-dependent speaker behavior. It is not an automatic phase-alignment system. Measure the actual arrivals and verify the final setting at the intended listening location. Copy or download the result to keep its units, temperature, assumptions and source direction together. Printing produces a compact result rather than the input controls. No account, microphone access or uploaded measurement file is needed.