Home Back

How to Calculate Energy When Given Wavelength

Energy Formula:

\[ E = \frac{h \times c}{\lambda} \]

meters
J·s
m/s

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is the Energy from Wavelength Calculator?

Definition: This calculator computes the energy of a photon based on its wavelength using Planck's equation.

Purpose: It helps physicists, chemists, and students determine photon energy for applications in quantum mechanics, spectroscopy, and photochemistry.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ E = \frac{h \times c}{\lambda} \]

Where:

Explanation: The energy of a photon is inversely proportional to its wavelength - shorter wavelengths correspond to higher energy photons.

3. Importance of Energy Calculation

Details: This calculation is fundamental in understanding quantum phenomena, designing optical systems, and analyzing atomic spectra.

4. Using the Calculator

Tips: Enter the wavelength in meters. Default values are provided for Planck's constant and speed of light, which can be adjusted if needed.

5. Frequently Asked Questions (FAQ)

Q1: Why is energy inversely proportional to wavelength?
A: This is a fundamental relationship in quantum mechanics where higher frequency (shorter wavelength) light carries more energy per photon.

Q2: What units should I use for wavelength?
A: The calculator uses meters, but you can convert from nanometers (1 nm = 10⁻⁹ m) or other units before entering.

Q3: Can I calculate wavelength from energy?
A: Yes, simply rearrange the formula: λ = (h × c)/E.

Q4: What's the energy range for visible light?
A: Approximately 1.6-3.1 eV (2.56-4.96 × 10⁻¹⁹ J) for 400-700 nm wavelengths.

Q5: How precise are the constants?
A: The values shown are rounded; for precise calculations use h = 6.62607015×10⁻³⁴ J·s (exact) and c = 299792458 m/s (exact).

Energy from Wavelength Calculator© - All Rights Reserved 2025