Various theories help to find new things. Through Science, an individual can solve so many things. Some units derive the inventions which are obtained by theories. Watts and Lumens are the units that help to derive the various fluxes in SI terms.

## Key Takeaways

- Watts measure power consumption, while lumens measure light output.
- To assess energy efficiency, compare lumens per watt (lm/W).
- High-lumen bulbs produce more light with lower wattage, reducing energy consumption.

**Watts vs Lumens **

The difference between Watts and Lumens is that Watt is a Standard unit to derive the radiant flux, whereas Lumen is a unit that helps in deriving the luminous flux. Both Watts and Lumens are units, but the deriving fluxes vary from each other.

A watt is a unit of radiant flux or power. It is to determine the rate at which energy had transferred. It was named after James Watt, who was an 18th-century inventor.

A kilowatt-second unit of power is equal to the output power of one joule per second. It is capable of producing up to 1/746 horsepower. Formula of Watts id W (joules per second) x A (amperes per second) = V (volts per coulomb) x W = watts.

In Contrast, the luminous flux is a measure of the total amount of light that a source produces. It is to determine the total amount of light that a flashlight or headlamp emits.

Lumen was known as a SI Unit, where One Lumen is the total quantity of visible light that a source emits. It is equivalent to 1.46 milliwatts of radiant electromagnetic Power.

**Comparison Table **

Parameters of Comparison | Watts | Lumens |
---|---|---|

Meaning | A watt is a unit of radiant flux or Power. | A lumen is a unit that derives the luminous flux. |

Inventor | The Watts unit had invented by James Watt in the 18th century. | The lumens unit had invented by William Henry Fox Talbot in the 18th century. |

Difference | The Watts unit uses to compute the power that absorbs by the bulb. | Lumens unit uses to calculate the light that had emitted from bulbs. |

Symbol | The symbol uses to denote the Watts is W. | Lumens had symbolized as lm. |

Base | The SI unit base for Watts is kg.m^2/S^3. | The unit base used for Lumens is 1 cd. sr |

**What is Watts?**

A watt is a unit of radiant flux or power. It had been named after James Watt, who was an 18th-century inventor. It was commonly used to determine the rate at which energy had transferred.

A kilowatt-second unit of power is equal to the output power of one joule per second. It is capable of producing up to 1/746 horsepower. Formula of Watts id W (joules per second) x A (amperes per second) = V (volts per coulomb) x W = watts.

The SI unit base for Watts is kg.m^2/S^3, where it is a SI unit used as a unit for radiant flux. The symbol denotes the Watts is the W. Watts unit used to compute the power that absorbs by the Power.

Watts is used for computing, but it does not talk about the bulb brightness. Watts will calculate according to the types of bulbs. Incandescent and fluorescent are the types of bulbs that vary the Watts values.

Watts can also use to measure in Kilowatts, where the used symbol is KW. The single ampere of electricity passes over the potential difference for a volt measured by the Watts.

An individual can experience this unit in science subjects and also in power consumption bills. These units will get change when changed into amperes, voltage, and some other units. The multiples that we use in Watts are

- Femtowatt
- Picowatt
- Kilowatt
- Nanowatt
- Microwatt
- Terawatt
- Petawatt

The above are some multiples of Watts where other multiples can produce in references. The Watt unit change according to the measuring element that depends on the physical quantities.

**What is Lumens? **

A lumen is a unit of luminous flux that is used to calculate the light that had emitted. The luminous flux is a measure of the total amount of light that a source produces.

The lumens unit had invented by William Henry Fox Talbot in the 18th century. It had used to determine the total quantity of light that a flashlight or headlamp emits.

The luminous flux is a measure of the total amount of light that a source produces. The unit base used for Lumens is 1 cd. sr where Lumens had symbolized as lm.

Lumen was known as a SI Unit, where One lumen is the total quantity of visible light that a source emits. It is equivalent to 1.46 milliwatts of radiant electromagnetic power.

William Henry had taken the lumen to check the invented process of salt and silver nitrate coated to a paper.

An individual can identify the light that it emits brightly or dimmer. The more lumens we find when the light is brighter, and the dimmer light produces low lumens.

We can represent it as lumens equal to output light. Lumens can convert into watts, and volts by calculating according to the methods. 90 Lumens (lm) is equal to 60 Watts (W).

Lumens and Watts have a connection as when the wattage is high, the bulb emits brighter. Usually, we can experience the lumens as a single lumen can shine like a birthday candle.

The lumens unit had correlated to Candela as 1lm = 1 cd. sr. The lumens that calculate the projector are called ANSI LUMENS, where the emitting light of the projector will calculate in ANSI LUMENS.

**Main Differences Between Watts and Lumens**

- A watt is a unit of radiant flux or power, whereas a Lumen is a unit of luminous flux.
- The Watts unit had invented by James Watt in the 18th century, and the Lumens had developed by William Henry Fox Talbot in the 18th century.
- The SI unit base for Watts is kg.m^2/S^3, where the Lumens base unit is 1 cd. sr
- The Watts unit uses to compute the capacity that absorbs by the power, whereas the Lumens unit uses to calculate the light emitted from bulbs.
- The symbol used to denote the Watts is W, whereas Lumens had symbolized as lm.
- Lumens will use to calculate the effuse light, whereas Watts computes the power of the bulb.

**References**

- http://nature.berkeley.edu/classes/es196/projects/2009final/QuirkI_2009.pdf
- https://ieeexplore.ieee.org/abstract/document/6119610/

Piyush Yadav has spent the past 25 years working as a physicist in the local community. He is a physicist passionate about making science more accessible to our readers. He holds a BSc in Natural Sciences and Post Graduate Diploma in Environmental Science. You can read more about him on his bio page.