# Illuminance Converter (lux / footcandle / phot / nox)

Convert illuminance between lux (lx = lm/m², SI base), kilolux (1 = 1000 lx), footcandle (1 = 10.7639104 lx), phot (1 = 10000 lx), and nox (1 = 0.001 lx). Converts via lux to the target unit and lists the equivalent value in all five units for reference. Reference values: full moon ≈ 0.25, office lighting ≈ 300–500, overcast day ≈ 1000, direct sunlight ≈ 100000 lux.

> Canonical page: https://elysiatools.com/en/tools/illuminance-converter

- **Category:** Math & Numbers

- **Keywords:** illuminance, illuminance conversion, lux, lx, footcandle, fc, phot, nox, lumens per square metre, lighting design, photometry

## Overview

Convert non-negative illuminance values between lux, kilolux, footcandle, phot, and nox. Enter a value, choose the input and output units, set the decimal places, and receive the converted value plus equivalent values in all five units.

## Inputs

- **Input unit** (select)
- **Value** (number): Illuminance in the selected Input unit. Must be non-negative.
- **Output unit** (select)
- **Decimal Places** (number)

## When to use

- Convert office lighting from lux to footcandles for lighting specifications.
- Compare bright outdoor conditions in lux, kilolux, phot, or nox.
- Check equivalent illuminance values across different photometry units.

## How it works

- Enter a non-negative illuminance value.
- Select the input unit: lux, kilolux, footcandle, phot, or nox.
- Select the output unit and choose between 0 and 10 decimal places.
- The converter calculates through lux and returns the selected conversion with all five unit equivalents.

## Use cases

- Lighting designers can convert illuminance measurements between SI and imperial units.
- Facility teams can compare office lighting levels with common reference values of 300–500 lux.
- Photometry and engineering students can verify relationships between lux, footcandle, phot, and nox.

## Frequently asked questions

### Which illuminance units does this converter support?

It supports lux, kilolux, footcandle, phot, and nox.

### What is the base unit for the conversion?

Lux is the SI base unit, equal to lumens per square metre (lm/m²).

### Can I convert lux to footcandles?

Yes. For example, 500 lux equals approximately 46.451521 footcandles.

### Does the result include other unit equivalents?

Yes. The result lists the equivalent value in all five supported units.

### How many decimal places can I display?

You can choose from 0 to 10 decimal places.

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