Enter the power of the light source and the wavelength into the calculator to determine the number of photons emitted per second. This calculator can also evaluate any of the variables given the others are known.

## Watts To Photons Per Second Formula

The following formula is used to calculate the number of photons emitted per second from a light source.

PS = (W * λ) / h

Variables:

- PS is the number of photons per second
- W is the power of the light source in watts (W)
- λ is the wavelength of the light (meters)
- h is the Planck’s constant (6.62607015 × 10^-34 m^2 kg / s)

To calculate the number of photons per second, multiply the power of the light source in watts by the wavelength of the light. Then, divide the result by Planck’s constant.

## What is Watts To Photons Per Second?

Watts to photons per second is a conversion factor used in physics to quantify the number of photons (light particles) emitted per second by a light source. The watt is a unit of power that measures the rate of energy conversion or transfer, while photons per second measures the number of photons emitted by a light source in one second. This conversion is particularly useful in fields such as quantum physics and photonics, where the behavior and properties of photons are studied.

## How to Calculate Watts To Photons Per Second?

The following steps outline how to calculate the Watts To Photons Per Second using the given formula:

- First, determine the power of the light source in watts (W).
- Next, determine the wavelength of the light in meters (λ).
- Next, gather the formula from above: PS = (W * λ) / h.
- Finally, calculate the Watts To Photons Per Second (PS).
- After inserting the values of W, λ, and h into the formula, calculate the result.

**Example Problem:**

Use the following variables as an example problem to test your knowledge:

Power of the light source (W) = 50

Wavelength of the light (λ) = 5 x 10^-7 meters

Planck’s constant (h) = 6.62607015 × 10^-34 m^2 kg / s