# Wavelength Calculator (λ = v/f)

Calculate wavelength from frequency and wave speed using λ = v/f. Presets for sound in air, sound in water, and light.

## What this calculates

Wavelength is the distance between consecutive crests (or troughs) of a wave. It is related to frequency and wave speed by the equation λ = v/f. This calculator works for any type of wave — sound, light, radio, water — as long as you know the frequency and the speed of the wave in the medium.

## Inputs

- **Frequency** (Hz) — min 0
- **Wave Speed** (m/s) — min 0 — Sound in air: 343, Light in vacuum: 3×10⁸
- **Wave Type Preset** — options: Custom Speed, Sound in Air (343 m/s), Sound in Water (1,480 m/s), Light in Vacuum (3×10⁸ m/s)

## Outputs

- **Wavelength** (m) — λ = v / f
- **Wavelength** (cm) — Wavelength in centimeters
- **Period** (s) — T = 1/f — time for one complete cycle
- **Angular Frequency** (rad/s) — ω = 2πf

## Frequently Asked Questions

**Q: What is wavelength?**

A: Wavelength (λ) is the spatial distance between two consecutive identical points on a wave, such as crest to crest or trough to trough. It is measured in meters and is inversely proportional to frequency: higher frequency means shorter wavelength, and vice versa.

**Q: Why does wave speed matter for wavelength?**

A: The same frequency produces different wavelengths in different media because waves travel at different speeds. For example, a 440 Hz sound wave has a wavelength of about 0.78 m in air (343 m/s) but about 3.36 m in water (1,480 m/s). The relationship λ = v/f captures this dependency.

**Q: What is the wavelength of visible light?**

A: Visible light has wavelengths between approximately 380 nm (violet) and 700 nm (red). Using λ = c/f where c = 3×10⁸ m/s, red light at 430 THz has a wavelength of about 700 nm, while violet light at 790 THz has a wavelength of about 380 nm.

**Q: What is the relationship between wavelength and energy?**

A: For electromagnetic waves, energy is inversely proportional to wavelength: E = hc/λ, where h is Planck's constant. Shorter wavelengths (like X-rays and gamma rays) carry more energy per photon than longer wavelengths (like radio waves). This is why ultraviolet light can cause sunburn but visible light generally cannot.

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Source: https://vastcalc.com/calculators/physics/wavelength
Category: Physics
Last updated: 2026-04-21