Wavelength Calculator
Calculate wavelength instantly in your browser — the published formula, worked locally with no data sent anywhere.
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What this tool does
Calculate wavelength instantly in your browser — the published formula, worked locally with no data sent anywhere. One formula covers every wave type — only the speed changes. For EM waves the medium values ignore dispersion (the tiny frequency-dependence of refractive index).
How to use the Wavelength Calculator
- Enter or select frequency.
- Enter or select frequency unit.
- Enter or select wave medium.
- Enter or select custom wave speed (m/s).
- Read the calculated result; change any measurement to compare alternatives.
Formula
wavelength λ = wave speed ÷ frequency. Electromagnetic waves use c = 299,792,458 m/s in vacuum (≈ c/1.000293 in air); sound in 20 °C air travels at 343 m/s.
- freq
- Frequency
- funit
- Frequency unit
- medium
- Wave medium
- speed
- Custom wave speed (m/s)
One formula covers every wave type — only the speed changes. For EM waves the medium values ignore dispersion (the tiny frequency-dependence of refractive index).
Worked example
For wavelength calculator, the following measurements illustrate the exact method: Frequency: 100; Frequency unit: 1e6; Wave medium: vacuum; Custom wave speed (m/s): 1500.
Inputs
- Frequency100
- Frequency unitMHz
- Wave mediumElectromagnetic — vacuum
- Custom wave speed (m/s)1500
Result
- Wavelength (m)3
- Wavelength (cm)299.79
- Frequency (Hz)100,000,000
- Period (s)0
- Wave speed used (m/s)299,792,458
Results explained
- Wavelength (m)
- Wavelength (m) from the formula above. One formula covers every wave type — only the speed changes. For EM waves the medium values ignore dispersion (the tiny frequency-dependence of refractive index).
- Wavelength (cm)
- Wavelength (cm) from the formula above. One formula covers every wave type — only the speed changes. For EM waves the medium values ignore dispersion (the tiny frequency-dependence of refractive index).
- Frequency (Hz)
- Frequency (Hz) from the formula above. One formula covers every wave type — only the speed changes. For EM waves the medium values ignore dispersion (the tiny frequency-dependence of refractive index).
- Period (s)
- Period (s) from the formula above. One formula covers every wave type — only the speed changes. For EM waves the medium values ignore dispersion (the tiny frequency-dependence of refractive index).
- Wave speed used (m/s)
- Wave speed used (m/s) from the formula above. One formula covers every wave type — only the speed changes. For EM waves the medium values ignore dispersion (the tiny frequency-dependence of refractive index).
Frequently asked questions
wavelength λ = wave speed ÷ frequency. Electromagnetic waves use c = 299,792,458 m/s in vacuum (≈ c/1.000293 in air); sound in 20 °C air travels at 343 m/s.
One formula covers every wave type — only the speed changes. For EM waves the medium values ignore dispersion (the tiny frequency-dependence of refractive index).
Every field is labelled with its unit — enter values in exactly the labelled unit and read the result in the labelled output unit. Fields with a unit symbol also support the site-wide imperial/metric switch, which converts before the formula runs.
It uses double-precision arithmetic and the published constants and formulas named on this page. The last displayed digit may be rounded, and real conditions can differ from the idealized model described in the assumptions.
Yes. Every calculation runs entirely in your browser; nothing you enter is uploaded, stored or shared.