2500 Par to Lux – Full Calculation Guide

2500 par is approximately equal to 37500 lux.

The conversion from par to lux depends on the wavelength and light source, but a standard average factor used is 1 par = 15 lux. This means, to convert par to lux, you multiply the par value by 15 to estimate the corresponding illuminance in lux.

Conversion Tool

Conversion Formula

The formula to convert par (Photosynthetically Active Radiation) to lux is:

lux = par × 15

This formula comes from the approximate relationship between par units, which measure photon flux density, and lux, which measures luminous flux per unit area. Since par focuses on photons useful to plants, and lux is weighted by human eye sensitivity, a rough conversion applies a factor of 15.

For example, converting 2500 par to lux:

• Multiply 2500 by 15
• 2500 × 15 = 37500 lux
• This means 2500 par corresponds to 37500 lux in illuminance.

Conversion Example

• Convert 1800 par to lux:
  • Multiply 1800 × 15
  • Result is 27000 lux
  • This shows 1800 par equals 27000 lux.
• Convert 3200 par to lux:
  • Calculate 3200 × 15
  • Equals 48000 lux
  • So, 3200 par corresponds to 48000 lux.
• Convert 1500 par to lux:
  • Multiply 1500 × 15
  • Gives 22500 lux
  • Thus, 1500 par is 22500 lux.
• Convert 2750 par to lux:
  • Multiply 2750 × 15
  • Result is 41250 lux
  • Meaning 2750 par equals 41250 lux.

Conversion Chart

This chart shows the conversion from par values between 2475 and 2525 into lux. You can find par value on the left column, and corresponding lux value on the right. It’s useful to check approximate lux for values near 2500 par without calculation.

Related Conversion Questions

• How many lux is 2500 par equivalent to in indoor lighting?
• What is the lux value for 2500 par in horticulture applications?
• Can 2500 par be converted to lux for LED grow lights?
• What formula should I use to convert 2500 par to lux?
• Is 2500 par equal to more or less than 35000 lux?
• How does 2500 par compare to lux in measuring plant light intensity?
• What lux does 2500 par represent under sunlight conditions?

Conversion Definitions

Par: Par stands for Photosynthetically Active Radiation, measuring the amount of light in the 400-700 nanometer wavelength range that plants use for photosynthesis. It counts the number of photons hitting a surface every second, usually expressed in micromoles per square meter per second (µmol/m²/s). Par is vital for plant growth studies and lighting design.

Lux: Lux is a unit of illuminance indicating how much luminous flux is spread over a given area. It measures visible light perceived by the human eye, with 1 lux equal to one lumen per square meter. Lux is used for assessing lighting levels in workplaces, homes, and outdoor environments to ensure adequate visibility and comfort.

Conversion FAQs

Why does the conversion from par to lux use a factor of 15?

The factor 15 comes from average spectral weighting between par, which counts photons in the 400-700 nm range, and lux, which weights light based on human eye sensitivity peaking around 555 nm. Because par measures photon quantity and lux measures perceived brightness, multiplying by 15 gives an approximate conversion under standard lighting conditions.

Can I use the same conversion factor for all types of light sources?

No, the factor 15 is an estimate based on average sunlight or white light. Different light sources like LEDs or fluorescent lamps have different spectra, which affect the par-to-lux ratio. For precise work, spectrum-specific conversions or direct measurements are necessary rather than a fixed multiplier.

Is converting par to lux always necessary for plant growth analysis?

Not always. Par directly measures the photons plants use for photosynthesis, which is more relevant than lux. Lux measures human-visible light, which may not correlate well with plant needs. However, converting to lux can help in general lighting assessments or when comparing to human lighting standards.

How accurate is this conversion for greenhouse lighting?

The conversion provides a rough estimate but may not be precise for greenhouse lighting because spectral quality, light source, and environmental factors influence the relationship. For critical applications, using specialized sensors that directly measure par or photosynthetic photon flux density is recommended over lux conversions.

Does ambient light affect the par to lux conversion?

Ambient light spectrum and intensity can influence the conversion because lux depends on human eye response and par counts photons useful to plants. Mixed light sources or shaded conditions can skew the ratio, making simple multiplication less accurate in non-standard lighting environments.

Last Updated : 22 July, 2025

Sandeep Bhandari

Sandeep Bhandari holds a Bachelor of Engineering in Computers from Thapar University (2006). He has 20 years of experience in the technology field. He has a keen interest in various technical fields, including database systems, computer networks, and programming. You can read more about him on his bio page.