# Wavelength and Frequency Calculator

URL: https://speedycalculator.com/calculators/physics/wavelength/
Last updated: 2026-10-25

> The wavelength calculator converts between frequency and wavelength using λ = v ÷ f. Choose light in a vacuum, sound in air or water, or enter any wave speed.

## Inputs

- Wave speed
- Frequency (Hz, kHz, MHz, GHz)

## Results

- Wavelength
- Period

## Formula

```
λ = v ÷ f
```

## Explanation

For any wave, speed equals frequency times wavelength. Higher frequency means shorter wavelength.

### How to use the Wavelength and Frequency Calculator

- **Wave speed**
- **Frequency**
- Want to work backwards? Type a value into **Wavelength** and **Frequency** is calculated for you.

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Divide the wave speed by the frequency.

### Inputs explained

FieldWhat to enterWave speedChoose one: Light in vacuum (299,792,458 m/s), Sound in air, 20 °C (343 m/s), Sound in water (1,481 m/s)FrequencyUnits: Hz, kHz, MHz, GHz

### What each result means

- **Wavelength** = [Wave speed] ÷ [Frequency]
- **Period** = 1÷[Frequency]

### Example values

How the main result changes when **Frequency** changes and everything else stays at the example values above:

Frequency (Hz)Wavelength (m)50,000,000675,000,0004100,000,0003125,000,0002.4150,000,0002200,000,0001.5

## Worked example

Inputs — Wave speed: Light in vacuum (299,792,458 m/s); Frequency: 100,000,000 Hz.

Results — **Wavelength = 3 m**; Period = 0.00000001 s.

## FAQ

**What is the wavelength of FM radio?**
About 3 m at 100 MHz.

**What wavelength is visible light?**
Roughly 380–750 nm.

**What formula does the Wavelength and Frequency Calculator use?**
λ = v ÷ f.

**Can I work backwards from the result?**
Yes. Type the result you want into Wavelength and the calculator finds the matching frequency.


## Sources

- [NIST – Fundamental physical constants](https://physics.nist.gov/cuu/Constants/)