Wave Speed Calculator
A 440 Hz note in air at 20 °C (343 m/s) has a wavelength of 0.779545 m, from λ = v/f.
0.779545454545454 m
Full answer, then cut to fewer decimals (not rounded):
- 0.779545454545454 m
- 0.77954545454545 m
- 0.7795454545454 m
- 0.779545454545 m
- 0.77954545454 m
- 0.7795454545 m
- 0.779545454 m
- 0.77954545 m
- 0.7795454 m
- 0.779545 m
- 0.77954 m
- 0.7795 m
- 0.779 m
- 0.77 m
- 0.7 m
- In nm
- 779545454.5 nm
- In µm
- 779545.4545 µm
- In mm
- 779.5454545 mm
- In cm
- 77.95454545 cm
- In km
- 0.0007795454545 km
- Period T = 1/f
- 0.002272727273 s
- Wavenumber 1/λ
- 1.282798834 m⁻¹
Step-by-step solution
- λ = v ÷ f
- λ = 343 ÷ 440
- λ = 0.7795454545 m
Wave Speed Formula
v = f λ
v wave speed, f frequency (Hz), λ wavelength; period T = 1/f
Worked Example
Concert A (440 Hz) travelling through air at 343 m/s:
- λ = v ÷ f
- λ = 343 ÷ 440
- λ = 0.7795454545 m
In µm: 779545.4545 µm · In mm: 779.5454545 mm · In cm: 77.95454545 cm · In km: 0.0007795454545 km · Period T = 1/f: 0.002272727273 s · Wavenumber 1/λ: 1.282798834 m⁻¹
Radio wavelengths
FM radio at 100 MHz has λ = 3 m; Wi-Fi at 2.4 GHz has λ = 12.5 cm. Antennas are often a quarter or half wavelength long.
More Waves and Optics Calculators
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n₁ sin θ₁ = n₂ sin θ₂
n refractive index of each medium, θ angle measured from the normal; critical angle θc = arcsin(n₂/n₁)
Example: Light passing from air (n = 1) into water (n = 1.333) at 30° to the normal: Angle of refraction θ₂ = 22.0301 °.
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Lens and Mirror Equation Calculator
1/f = 1/dₒ + 1/dᵢ, m = −dᵢ/dₒ
f focal length, dₒ object distance, dᵢ image distance (real-is-positive convention); m magnification
Example: An object 15 cm from a converging lens with f = 10 cm: Image distance dᵢ = 30 m.
Frequently asked questions
What is the speed of sound and light?
Sound in air is about 343 m/s at 20 °C (faster in water, ~1480 m/s); light in vacuum is exactly 299,792,458 m/s.
What changes when a wave enters a new medium?
Its speed and wavelength change, but the frequency stays the same, which is why a sound’s pitch does not change underwater.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures .
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Wave Speed Calculator. Retrieved October 25, 2026, from https://scientificconverters.com/calculators/wave-speed-calculator/
IEEE
Scientific Converters, "Wave Speed Calculator," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/calculators/wave-speed-calculator/