Frequency Wavelength Converter

Frequency

Fill frequency or wavelength. You can fill both.

Frequency unit HzkHzMHzGHzTHz

Wavelength

For light, common units are nm or µm.

Wavelength unit mcmmmµmnmpm

Wave speed preset Light in vacuum (299,792,458 m/s)Sound in air (~343 m/s)Sound in water (~1,482 m/s)Sound in steel (~5,960 m/s)Custom speed

Preset sets speed automatically, unless custom.

Wave speed value

Speed unit m/skm/s

Calculate Reset

For a wave traveling at speed v, frequency f, and wavelength λ:

• v = f × λ
• λ = v / f
• f = v / λ

Derived values include the period T = 1/f and angular frequency ω = 2πf. Photon energy is shown as E = hf when relevant.

1. Enter either frequency or wavelength. You may enter both.
2. Select units that match your input values.
3. Choose a wave speed preset, or select custom speed.
4. Click Calculate to view results above the form.
5. Use Download CSV or Download PDF for exports.

Professional guide to frequency and wavelength

1) Why frequency–wavelength conversion matters

Modern systems talk in either frequency or wavelength, depending on the industry. Radio engineering typically specifies frequency, while optics often prefers wavelength. Converting accurately lets you compare technologies on the same scale and avoid unit mistakes that can propagate into design and documentation.

2) The governing relationship for traveling waves

The calculator is built around v = f × λ, where v is wave speed, f is frequency, and λ is wavelength. Once two quantities are known, the third is determined. This is true for sound, water waves, and electromagnetic radiation, as long as the chosen speed matches the medium.

3) Using the speed presets responsibly

Electromagnetic waves in vacuum use 299,792,458 m/s. In real materials, light travels slower, so wavelength changes while frequency stays set by the source. For acoustics, the sound-speed presets provide practical starting points: about 343 m/s in air and roughly 1,482 m/s in water.

4) Practical ranges by application

FM broadcasting near 100 MHz corresponds to wavelengths around 3 m. A common Wi‑Fi channel near 2.4 GHz produces a wavelength near 12.5 cm. Visible light spans roughly 400–700 nm, equivalent to about 430–750 THz in frequency.

5) Interpreting period and angular frequency

The period T = 1/f expresses how long a single cycle takes. For a 1 MHz ultrasound signal, the period is 1 µs. Angular frequency ω = 2πf is common in vibration, control, and wave equations, and it pairs naturally with sinusoidal models.

6) Energy context for electromagnetic radiation

When the wave is electromagnetic, photon energy follows E = hf. Higher frequency means higher photon energy. For example, frequencies in the visible range yield energies of a few eV, while microwave frequencies produce much smaller energies, useful for understanding heating, sensing, and detector selection.

7) Validating inputs with the consistency check

If you enter both frequency and wavelength, the tool computes the implied values and reports mismatch percentages. This helps you catch a wrong unit (like mm vs m) or an incorrect speed choice. In measurement workflows, this serves as a fast sanity check before exporting results.

8) Reporting results clearly in lab and design notes

Use consistent units and include the assumed wave speed in your record. This calculator exports key values to CSV and PDF, making it easy to attach to a lab notebook, a test report, or a design review. Clear reporting reduces ambiguity and supports reproducible calculations.