Calculator
Example Data Table
| Medium | Speed (m/s) | Frequency (Hz) | Wavelength (m) | Notes |
|---|---|---|---|---|
| Air (20°C) | 343 | 100 | 3.43 | Low bass tone, long wavelength. |
| Air (20°C) | 343 | 1,000 | 0.343 | Common test tone. |
| Air (20°C) | 343 | 10,000 | 0.0343 | Short wavelength, high pitch. |
| Water (≈20°C) | 1,482 | 1,000 | 1.482 | Sound travels faster than in air. |
| Steel | 5,960 | 1,000 | 5.96 | Very fast propagation in solids. |
Formula Used
- Wave relation: v = f × λ
- Wavelength: λ = v / f
- Frequency: f = v / λ
- Air speed estimate: v ≈ 331.3 + 0.606T (T in °C)
- Period: T = 1 / f
- Angular frequency: ω = 2πf
- Wave number: k = 2π/λ
How to Use This Calculator
- Choose what you want to calculate: wavelength, frequency, or speed.
- Select a medium preset, or choose Custom for your own speed.
- If using air, enter the temperature to estimate the speed.
- Enter the required known values (frequency and/or wavelength).
- Click Calculate to see results above the form.
- Use Download CSV or Download PDF to export.
Audio Wavelength and Frequency Article
Understanding the Wave Relationship
Sound links speed, frequency, and wavelength through v = f × λ. If speed stays constant, doubling frequency halves wavelength. This helps compare bass notes with long wavelengths to treble notes with short wavelengths.
Typical Speeds by Medium
In air near room temperature, sound moves about 343 m/s. In water it is roughly 1,482 m/s, and in steel around 5,960 m/s. Faster media produce longer wavelengths at the same frequency, which matters for sonar and vibration studies.
Temperature and Air Speed
Air speed rises with temperature because molecules move faster. A useful estimate is v ≈ 331.3 + 0.606T, with T in °C. For example, 0°C gives about 331 m/s, while 30°C gives about 349 m/s, changing calculated wavelength by several percent.
Audible Frequency Bands
Typical human hearing spans about 20 Hz to 20,000 Hz. Below 20 Hz is infrasound, common in earthquakes and large machinery. Above 20 kHz is ultrasound, used in cleaning baths and medical imaging. The calculator flags these ranges as a quick check.
Practical Examples
A 1,000 Hz tone in 20°C air has a wavelength near 0.343 m. A 100 Hz bass note stretches to about 3.43 m. In water, the same 1,000 Hz tone becomes about 1.482 m long, which explains why underwater sounds travel far. Concert A at 440 Hz in 20°C air has λ ≈ 0.78 m. A subwoofer at 40 Hz reaches about 8.6 m, so small rooms can’t fit a full wave and standing waves dominate. This guides speaker placement and treatment.
Unit Handling and Precision
You can enter frequency in Hz, kHz, or MHz and wavelength in meters, centimeters, millimeters, feet, or inches. Internally, values convert to base units, then the selected rounding precision controls display and exports. Using more decimals is helpful for lab work.
Using Period, Omega, and Wave Number
Period gives the time for one cycle, T = 1/f. Angular frequency ω = 2πf is useful in signal processing and differential equations. Wave number k = 2π/λ describes spatial cycling and appears in acoustics, room modes, and dispersion studies.
Common Measurement Tips
Measure frequency with a tuner or FFT app and estimate wavelength from spacing between repeating pressure patterns. Keep the medium realistic: air speed differs with temperature, while solids vary by alloy and structure. When results look odd, verify units and input magnitude.
FAQs
How is frequency different from pitch?
Frequency is a physical measurement in hertz. Pitch is how your brain interprets frequency, influenced by loudness and harmonics. Two sounds can share the same frequency but feel different because their waveforms contain different overtones.
Why does wavelength change when temperature changes?
In air, sound speed increases as temperature rises. Since λ = v/f, a higher v makes wavelength longer for the same frequency. If you keep wavelength fixed instead, the computed frequency increases.
When should I calculate sound speed instead of using a preset?
Calculate speed when you already know both frequency and wavelength from measurements, such as lab demonstrations or standing-wave experiments. Using v = f×λ can estimate the effective speed in your specific setup.
Which medium preset is best for everyday audio?
Use Air for normal listening and set temperature close to your room. Water and steel presets are useful for underwater acoustics and vibration in solids. If you have a datasheet value, choose Custom and enter it directly.
Can I use the calculator for ultrasound or infrasound?
Yes. Enter any frequency value and the tool will compute wavelength and related metrics. The range hint will label values below 20 Hz as infrasound and above 20 kHz as ultrasound for quick validation.
Why do I get unrealistic results?
Most errors come from unit mix-ups. Check kHz vs Hz, mm vs m, and ensure values are greater than zero. Also confirm the selected medium or custom speed matches your situation; speed strongly affects wavelength.
Do exports keep my selected units and precision?
Yes. CSV and PDF include both the displayed values in your chosen units and the base-unit values (Hz, m, m/s). The rounding precision setting controls how many decimals are shown and exported.