Calculate Acoustic Speed of Sound (v = 331.3 + 0.606 · T_C)

Enter your physical parameters below to compute verified sound speed metrics.

Air temperature in degrees Celsius (e.g. 20.0 °C = 68 °F).
Select physical propagation medium.

Calculation Results

Primary Metric Output --
Metric Breakdown 1 --
Metric Breakdown 2 --
Metric Breakdown 3 --
Metric Breakdown 4 --
Metric Breakdown 5 --
Mathematical Standard --

Calculated using verified physical methodology: Speed of Sound in Air: v_{air} = 331.3 \cdot \sqrt{1 + \T_C / 273.15} \approx 331.3 + 0.606 \cdot T_C
Mach Number: \text{Mach} = \v / v_{sound}

*Note: Results represent longitudinal acoustic pressure wave speed.

Quick Summary

The Speed of Sound Calculator evaluates acoustic wave propagation speed ($v \approx 331.3 + 0.606 \cdot T_C$) in air across temperatures and in liquids/solids, outputting values in m/s, km/h, mph, and Mach numbers.

Formula Explanation

Speed of Sound in Air: v_{air} = 331.3 \cdot \sqrt{1 + \T_C / 273.15} \approx 331.3 + 0.606 \cdot T_C
Mach Number: \text{Mach} = \v / v_{sound}

How It Works

The Speed of Sound Calculator uses air temperature ($T_C$ in °C) to calculate sound speed in air ($v = 331.3 + 0.606 T_C$) or applies standard material sound speeds for water, seawater, steel, and aluminum. It outputs speed in m/s, km/h, mph, Mach 1 ratio, and 1 kHz wavelength.

Step-by-Step Worked Example

Practical Problem: Calculate the speed of sound in dry air at room temperature $T_C = 20.0^\circ\text{C}$ (68 °F).

  1. Step 1: Identify Input Parameters: Air Temperature $T_C = 20.0^\circ\text{C}$, Medium = Dry Air.
  2. Step 2: Apply Air Temperature Sound Speed Formula: $v = 331.3 \times \sqrt{1 + \20.0 / 273.15}$.
  3. Step 3: Execute Linear Approximation Cross-Check ($v \approx 331.3 + 0.606 \times 20$): $v \approx 331.3 + 12.12 = 343.42\text{ m/s}$.
  4. Step 4: Execute Exact Square Root Formula: $v = 331.3 \times \sqrt{1.07322} = 331.3 \times 1.03596 = 343.21\text{ m/s}$.
  5. Step 5: Convert and Interpret Speed Units: Speed of Sound $v = 343.21\text{ m/s} = 1,235.57\text{ km/h} = 767.75\text{ mph} = 1.000\text{ Mach}$. Wavelength at 1 kHz: $\lambda = \343.21 / 1000 = 0.343\text{ meters}$ (34.3 cm).

Real-World Calculation Examples

Scenario 1: Room Temperature Dry Air (20°C)

Parameters: $T_C = 20.0^\circ\text{C}$, Medium = Dry Air

Result: $v = 343.21\text{ m/s}$ (1,235.57 km/h, 767.75 mph, Mach 1.00). Standard acoustic speed.

Scenario 2: Freezing Winter Air (0°C)

Parameters: $T_C = 0.0^\circ\text{C}$, Medium = Dry Air

Result: $v = 331.30\text{ m/s}$ (1,192.68 km/h, 741.10 mph, Mach 0.965). Freezing air sound speed.

Scenario 3: Ocean Submarine SONAR in Seawater

Parameters: Medium = Seawater (20°C)

Result: $v = 1,531.00\text{ m/s}$ (5,511.60 km/h, 3,424.75 mph). Underwater SONAR speed.

Scenario 4: Ultrasonic Testing in Structural Steel

Parameters: Medium = Structural Steel

Result: $v = 5,960.00\text{ m/s}$ (21,456.00 km/h, 13,332.14 mph). Metal NDT ultrasonic speed.

Key Benefits of Using This Calculator

Temperature Precision Formula

Uses exact thermodynamic square root temperature formula ($v = 331.3 \sqrt{1 + T/273.15}$) for air speed.

Acoustic & Sonar Applications

Ideal for SONAR depth sounders, ultrasonic NDT testing, and architectural acoustics.

Multi-Unit Readouts

Outputs sound speed in m/s, km/h, mph, and Mach number.

100% Free & Client-Side

Executes locally in your browser with zero latency or web server transmission.

Frequently Asked Questions (FAQ)

What is the speed of sound?

The speed of sound is the distance traveled per unit time by an acoustic compression wave propagating through an elastic medium (v = sqrt(K/rho) or v = 331.3 + 0.606 * T_C in air).

What is the speed of sound in air at room temperature (20°C)?

Approximately 343.2 m/s (1,235.5 km/h = 767.8 mph = 1,126 ft/s).

Does air pressure affect the speed of sound?

No! For an ideal gas, changes in air pressure and density cancel out, so speed of sound depends strictly on TEMPERATURE, not atmospheric pressure.

Why does sound travel faster in solids and liquids than in air?

Because solids and liquids have much higher elastic bulk modulus K and tighter interatomic bonds than compressible gases (v = sqrt(K / rho)).

What is Mach 1?

Mach 1 is a dimensionless ratio equal to the speed of an object divided by the local speed of sound in the surrounding medium (Mach = v_object / v_sound).

What is a sonic boom?

A sonic boom is an explosive shockwave sound created when an object travels faster than Mach 1 (supersonic speed), causing constructive wave interference.

How fast is sound in water vs steel?

Freshwater v = ~1,481 m/s (~4.3x faster than air); steel v = ~5,960 m/s (~17x faster than air).

How estimates lightning distance using speed of sound?

Count seconds between seeing lightning flash and hearing thunder; divide by 3 to estimate distance in kilometers (or divide by 5 for miles).

Does humidity affect the speed of sound in air?

Slightly! Humid air is less dense than dry air (water vapor H2O molecular mass 18 vs N2/O2 average 29), increasing sound speed by up to ~0.35%.

What is the formula for speed of sound in an ideal gas?

v = sqrt(gamma * R * T / M), where gamma is adiabatic index (1.4 for air), R is gas constant, T is Kelvin temp, and M is molar mass.