Best PAR Light Meter [Updated!] | Why You Need a PAR Meter

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by Morgan

Last update:

May 6, 2024

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3 Top PAR Light Meters

SpotOn Quantum PAR And DLI Meter

SpotOn Quantum PAR and DLI Meter displays real-time photosynthetic light levels on plant canopies and provide information on light uniformity.


  • DLI Mode shows an average 24hrs PPFD
  • Works with any light source
  • Comes with a removable stand, magnetized screw, protective pouch, and a carabiner clip
Advanced Quantum PAR Meter

2. [Best For Experienced Growers] Advanced Quantum PAR Meter 

The Advanced Quantum PAR Meter ppfd Meter for led Grow Lights is ideal for experienced indoor and outdoor growers which provides various advanced features like CALI Function, LOG Feature, RCFS Function, and a large LCD Display.


  • Lightweight and Easily Portable
  • PAR Meter with Split Sensor
  • High Precision Measurement with upto 100 Groups Datalog
AIOMEST AI-881E Digital Light Meter

3. [Best For The Money] AIOMEST AI-881E Digital Light Meter

Digital Light Meter for LED Plant grow lights and indoor outdoor lights that can display environment temperature and light at the same time.


  • Simple, easy to use and pocket-friendly
  • Wider light measurement range
  • Hand-held foot candle meter

Why is a PAR Light Meter so important?

A PAR Light Meter allows growers to measure the intensity and quality of light across different parts of their garden, ensuring that each plant receives the optimal amount of light it needs.

This tool measures the light intensity in terms of PPFD-Photosynthetic Flux Density. Indoor farmers and researchers use PAR meters to supplement or complement sunlight with artificial lighting, especially during the winter months when natural light is scarce. By providing precise measurements, these meters help in adjusting the light sources to ensure plants are not just surviving, but flourishing.

In a nutshell, a PAR light meter is to plants what a nutrition label is to food. It doesn't just tell you that there's light; it tells you how much of that light is actually beneficial for the plants. For anyone looking to maximize their yield and optimize their growth environment, a PAR light meter is not just useful—it's essential. 

So, whether you're a seasoned indoor farmer or a curious green thumb, understanding and utilizing a PAR light meter could be the difference between a good harvest and a great one. Dive into the world of PAR light meters and watch your garden thrive under the right light!

What a PAR lightmeter does is calculates the proper PAR value and measuring light intensity from led grow lights so you can adjust the light specifically to plant growth stage. In short, a light meter for plants.

Because plants thrive on light and light spectrum, a PAR light meter can tell you exactly what light to give your plant at what time. Thus, having a PAR light meter can enhance your plants growing indoors by maximizing beneficial lights that your plants receive.

How to use a PAR Light Meter for Optimal Plant Growth?

Here's a step-by-step guide on how to use a PAR light meter effectively:

1. Understand the Meter: Before you start, it's crucial to understand the readings the PAR meter provides. It measures the light intensity in terms of PPFD (Photosynthetic Photon Flux Density) which tells you how many photons from the PAR spectrum are hitting a specific area every second.

2. Positioning the Sensor: Place the sensor of your PAR meter where your plants are or will be. Most meters have a detachable sensor that you can position at plant canopy level.

3. Taking Measurements: Turn on your meter and point the sensor towards your light source. The meter will then give you a reading in micromoles per meter squared per second (μmol/m2/s), indicating the light intensity.

4. Assess the Entire Area: To get an accurate understanding of the light distribution, take measurements across the entire footprint of your grow light. This helps ensure that all plants receive adequate light.

5. Adjust Your Lights: Based on the readings, adjust the height and position of your grow lights to provide even coverage. Try experimenting with different heights to find the optimal setting.

6. Record Your Data: Keep a log of your readings and adjustments. This historical data can be invaluable for troubleshooting and improving your indoor garden setup.

7. Regular Checks: Light conditions can change, so it's important to regularly use your PAR meter to monitor the light intensity and make adjustments as needed.

By following these steps, you can use a PAR light meter to fine-tune your indoor garden's lighting, ensuring your plants grow healthy and strong.

Not sure what Photosynthetically Active Radiation (PAR) light meter for grow lights to use? Below are reviews of the best PAR light meters. Finding the best PAR light meter will help your plants thrive under perfect conditions for growing indoors.

Best PAR Light Meters Reviews


This Quantum PAR Meter senses actual photosynthetic lights on plant canopies. Works with any light source including modern LED grow lights. The DLI mode calculates average light over 24 hours.

SpotOn Quantum PAR And DLI Meter

The SpotOn Quantum PAR and DLI Meter allow comparisons to light levels anywhere on earth. Scan mode averages PAR over the area being scanned. Provides important information on light uniformity. The standard default mode takes instant PPFD readings with a .75" easy-to-read LCD screen. It is lightweight yet sturdy, the SpotOn PAR meter is scientific grade and reasonably priced as compared to big brands. The device comes with an extension wand to allow readings to be taken further into the plant canopy which is sold separately. It also comes with its own removable stand which can be used as a soil stake. Also has a magnetized screw for quick attachment to metal posts for DLI mode. It also includes a protective pouch and carabiner clip for storage. The device is made up of aluminum and plastic and weighs around 77gms. The package consists of a padded zipper case with a carabiner, a product manual, a stake/stand attachment, and a magnetized back screw.

Customers like the ease of use and performance of the electronic sensor. For example, they mention it's simple, works great, and takes only a minute to set up.

SpotOn Quantum PAR And DLI Meter Amazon Reviews

2. [Best For Experienced Growers] Advanced Quantum PAR Meter 


The Advanced Quantum PAR meter accurately measures Photosynthetically Active Radiation (PAR) in the 400-700 nm wavelength and 0-3999 μmol/m²/sec range for plants LED grow lights, and ±1 μmol/m²/sec repeatability ensures well for reliable and accurate readings. This device is also able to record up to 100 groups of data, easily and conveniently for you to review the recent data storage and quickly optimize the light conditions for indoor and outdoor growing plants.

Advanced Quantum PAR Meter

The par meter for plants features 2 cables for the remote sensor to the main unit connection, one is a 4.9ft coiled cable, another is a 12ft straight cable that offers convenience and flexibility for your quantum light measurement needs. The large LCD screen of the plant light meter provides effortless viewing of PAR (PPFD) readings and battery strength. It prompts battery replacement and features convenient hold functions for tracking. This PPFD meter Tester is lightweight and easily portable for testing growing light intensity in various locations like fields, indoors, backyards, and nurseries. It can also be mounted with the 1/4''tripod screws provided on the main unit. The device requires 2 AAA batteries and weighs 115g approximately, excluding batteries and cables, ensuring portability and ease of handling.

Advanced Quantum PAR Meter Amazon Reviews

3. [Best For The Money] AIOMEST AI-881E Digital Light Meter


This Digital Light Meter has a handheld Foot Candle Meter whose illuminance measurement ranges between 0.1~300,000Lux (0.01~30,000FC). It provides a resolution of 0.1Lux/FC along with a high accuracy of ±4% on average. 
AIOMEST AI-881E Digital Light Meter

AIOMEST AI-881E Digital Light Meter is an ideal light level detector for photography, plant growing lights, LED, sunlight, aquariums, tanks, and so on. This photodetector has a silicon diode filter that can rotate 270° for every corner and every angle measurement easily and selects the optimal measuring angle and gets the most accurate reading of lighting levels at the front. The Digital Light Meter can display environment temp and light at the same time. The values are displayed in different units like °F/℃; Lux/ FC (Foot Candle). It helps to adjust the most suitable lights and temp bets suitable for the plants. It has an accurate Foot Candle Meter that takes quick samples 2~3 times per second for precise testing, stores up to 33 sets of data records, and has an ambient temperature display. It is great to use this lumens device for continuous data collection, comparison, and analysis. The device comes with 1 years warranty and lifetime tech support to let you buy freely. This lument tester also comes with a storage bag, 1.5V * 2 batteries, and a screwdriver. It is user-friendly with Max/Min modes, a Bar graph level indicator, and a  Backlit screen.

AIOMEST AI 881E Digital Light Meter Amazon Reviews

This is the PAR light meter for those that want perfection. Perfection does come with a price tag, but if money is not an issue and you want to grow the biggest buds, then check it out.

Apogee Instruments MQ-500 Full Spectrum Quantum PAR Meter Telescopic Wand Bundle

The MQ-500 by Apogee comes with a handheld meter for spot metering the colored PAR light spectrum in tight areas around your grow room. Easy to adjust and move around your plants from the canopy to the trunks, so you can tell what colors dissipate and where the strongest PAR is.

The sensor uses a blue enhanced photodiode made from silicon along with optical filters. In other words, it is well engineered for the job it is intended to do. Highly accurate results are what happens when using this light meter. The spectrum range is between 389 to 692 nm with a 180-degree view to pull in more PAR lighting.  The sensor is also waterproof which can be beneficial after feeding your plants as to not break due to moisture.

This PAR light meter is so good that it is backed by a 4-year warranty and is made in the USA. This PAR meter works very well and is one of the best PAR meters available for LED lights.

Apogee Instruments MQ-500 Full Spectrum Quantum PAR Meter Telescopic Wand Bundle Amazon Reviews
The Light Meter measures luminosity from 0 to 200,000 Lux and ambient temperature with highly accurate results. It has a high accuracy of ±3% rdg, ± 8 dgts (<10,000 Lux), ±4% rdg, ±10 dgts (>10,000 Lux).
Light Meter Digital Illuminance Meter

The device comes with 4 digital color LCD screen, has MIN/Max readings, data hold, auto power off, and low battery indication features. It has a wide range of applications like it can used as a lux light meter for set design, factory, office, or home use. It is a lightweight and compact device with 2 years long period warranty. It gives accurate measurements & fast responses. At twice per second frequency, it has a high response rate so you can be rest assured to get both fast and quality readings. It is easy to use and it has features of a uniquely designed 4 digital color LCD screen so you can check your readings any time of the day. You can also easily check if it's running out of juice with the low battery indication or simply enjoy the auto power-off function that will be enabled automatically when not in use after 15 minutes. It is a versatile application that is lightweight and ultra-compact, you can take it anywhere you need. The light meter has a wide range of applications including but not limited to use in schools, factories, warehouses, office or home for any photography projects, set and scenic design, and more. The device uses a photodetector of silicon photodiode with spectral response filter and requires 3 x 1.5V AAA batteries with at least 60 hours of battery life.

Customers like the quality, ease of use, and value of the photographic light meter. For example, they mention it works well for most lights, the instructions are easy to follow, and the screen is easy to understand. That said, opinions are mixed on accuracy, readability, appearance, and temperature.

Light Meter Digital Illuminance Meter Handheld Ambient Temperature Measurer Amazon Reviews
The Quantum PAR Meter measurement range is between 0 and 5000 μmol/m²/sec. The cut-on wavelength is 400 nm and the cut-off wavelength is 700 nm with a tolerance of ±10 nm, which indicates that the meter is designed to measure the PAR within this defined waveband, providing accurate and reliable readings of the amount of light energy available for photosynthesis.
Quantum PAR Meter Full-Spectrum High Precision PPFD Tester

 It has the capability to store up to 100 measured values. This allows the user to easily track and review previous readings, providing a record of the changes in PAR over time. Additionally, it has a real-time display feature that shows the last four recorded data, providing a quick and convenient way for the user to view recent measurements. This feature is particularly useful for monitoring and tracking changes in light energy levels in real-time, allowing for prompt and informed decisions to be made. A PAR meter is a valuable tool for growers, scientists, and researchers, providing accurate and reliable measurements of the amount of light energy available for photosynthesis, allowing for improved plant growth, increased energy efficiency, better crop management, and increased understanding of plant needs. It comes with a tripod socket to provide a convenient and practical way to securely attach the meter to a tripod (not included in the set), ensuring stability and accuracy during measurements, and providing greater flexibility in taking measurements. It is a portable, easy-to-use, flexible, and convenient tool for measuring PAR levels. It is a compact and lightweight design making it easy to carry the meter from one location to another, allowing for measurements to be taken in different parts of a greenhouse, growth chamber, or field. It has an ergonomic and user-friendly interface.

Customers like the ease of use, quality, accuracy, value, and performance of the lab supply. They mention that it's easy to use, provides credible measurements, and is a great tool for metering different lights. They appreciate the value for money and say it works well for adjusting PAR.

Quantum PAR Meter Full Spectrum High Precision PPFD Tester Amazon Reviews
DANOPLUS Light Lux Meter is equipped with a high-tech sensor, the accuracy of lux reading is ±4% ±10dgts; 400~700nm spectral range.
Light Meter Digital Lux Meter

This light meter is designed with 4 lux range settings, 200/2,000/20,000/200,000, and 0 to 20,000-foot candles(FC) unit switchable. It is equipped with a 360-degree rotating sensor, which is separated from the light meter, and can adjust suitable positions to ensure accurate measurements. The device provides features like MIN/MAX readings, Data Hold, Auto Power Off & Disable Auto Power Off, Auto Range Selection, and Low Battery Indication. This compact Light Meter is used for measuring the brightness of visible light (400~700 nm spectral range), it's suitable for factories, hospitals, schools, homes, offices, etc. The device requires 3 AAA batteries.

Light Meter Digital Lux Meter Handheld Illuminance Light Meter Amazon Reviews
Extech Light Meter measures white and color LED lighting and standard light sources like fluorescent, metal halide, high-pressure sodium, and incandescent with a range of up to 400,000 lux (40,000 Fc).
Extech LT45 LED Light Meter

It uses Lux or Foot Candle units. The package is lightweight, about 1.1 pounds. The device requires 2 Lithium Ion batteries. The device provides a basic accuracy of ±3% and weights 8.8oz (250g). The kit includes an Extech LT45 LED Light Meter, a light Sensor with a protective cover, and a coiled cable expandable to 59” (1.5m). It includes a 9-volt Battery, a hard case, and a user manual.

Customers like the ease of use, performance, portability, and quality of the thermometer. They mention that it's user-friendly, works well in a commercial environment, and is portable. Some are happy with the value. That said, opinions are mixed on accuracy.

Extech LT45 LED Light Meter Amazon Reviews

Final Word About The Best PAR Light Meters

You may be tempted when searching for PAR meters to purchase a cheap model. It’s all in the details.

No matter your light sources, if you are an indoor gardener looking for the best results, a PAR light meter might be the thing that gets you there. It's not just about providing light to your plants; it's about providing the right kind of light. The PAR meter helps you measure the quality of light that's crucial for plant photosynthesis. With a PAR meter, you can ensure your plants are getting the exact amount of light they need for optimal growth. Data is what drives a successful indoor garden and by adding a PAR meter to the mix you are enhancing your garden by knowing exactly what color light is hitting your plant and thus growing them into large and beautiful specimens. Hopefully, you can see the importance of color temperature as it relates to plants.

Optimizing environmental light levels can only enhance your growing process for plants. A good color meter is a must! Remember, light is just one aspect of plant care, but it's a vital one that can significantly impact your garden's success. Happy gardening!


1. Are PAR meters worth it?

PAR meters are useful tools for growers in that they provide useful information regarding the amount of photosynthetic light reaching the sensor. The way plants perceive light is different from how humans see it. Light wavelengths between 400 and 700 nanometers are beneficial to plants, according to studies.

2. How do you measure PAR with LED lights?

PAR is a measurement of the light's ability to support photosynthesis. It can be measured in PAR watts per square meter, or µmol/s per square meter.
PAR meters are used to measure the amount of light that a plant receives and can be used to determine how much supplemental lighting is needed for plants grown indoors.

3. What should my PAR meter read?

The PAR measurements for your plants should be between 400 and 600 PPFD as they proceed through veg and you want to foster robust, vegetative development during this time.

4. Can you convert LUX to PAR?

The answer is no, you cannot convert LUX to PAR. The unit of measurement for the amount of light that falls on a surface is lux and it doesn't have an equivalent in the PAR system.

5. What is the difference between PAR and PPFD?

The difference between PAR and PPFD is that PAR measures the amount of light in one area, while PPFD measures the total amount of light energy being emitted by a surface.

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About the author 


I discovered the benefits of Cannabis at a young age in 2002, with years of trial and error, my knowledge grew just like my plants. As my love for cannabis unfolded I began to teach and learn, trying to gain as much information and practical growing experience.

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