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Unit Conversions · Light & radiation

Illuminance Converter

Convert illuminance among lux, kilolux, foot-candles, and phot while keeping the incident-area basis explicit.

Unit Conversions · Light & radiation

Convert illuminance

Private in-browser conversion · common equivalents included
Illuminance Converter — visual relationshipUses the current inputs
Illuminance Converter— lx—source → geometry or spectrum → declared light quantity
The visual explains this calculator’s quantity and updates from the entered values. It does not add measurement accuracy or infer missing physical data.
  1. 1EnterProvide the known values
  2. 2CalculateResults update automatically
  3. 3VerifyReview the details and units
Try an example

Enter one finite number. This quantity is treated as a magnitude, so the value cannot be negative. Select explicitly labeled units—especially where US, Imperial, decimal, or binary conventions differ. Results stay in this browser.

Conversion result

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Enter valid values to see the result.

Your entries are calculated in this browser and are not submitted to 365CALCS.COM.

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Understand the physical quantity

What is Illuminance?

Photometry describes light as weighted for human vision, while radiometry describes physical radiant power. Flux, intensity, illuminance, luminance, irradiance, wavelength, frequency, and photon energy are related but distinct quantities.

This converter preserves the entered illuminance while changing its stated unit.

The relationship

Keep quantity and basis explicit

See the workflow

What the calculator is doing

Worked context

Read the output in context

1 foot-candle equals approximately 10.76391 lux.

Interpret with care

Important boundary

Illuminance describes luminous flux incident per area; it is not luminance or total lumens.

The result does not select a lighting standard, certify compliance, predict perception, or replace calibrated photometry and optical design.

Browse Light & radiation for related physical quantities.

Quick guide

How to use this calculator

  1. Enter the value exactly as recorded, then choose its source unit and the unit you need.
  2. Check regional and technical qualifiers in the unit names. US and Imperial gallons, force and mass, absolute temperatures and temperature differences, and decimal and binary data prefixes are deliberately separate.
  3. Use the selected result first, then open the common-equivalents table when you need to compare several standards without re-entering the value.

Calculation method

How the illuminance converter works

The entered illuminance is converted once to the canonical lux basis and then from that basis to the selected output unit.

Illuminance describes luminous flux incident per area; it is not luminance or total lumens.

Worked example

Illuminance example

1 foot-candle equals approximately 10.76391 lux.

source value × source-to-lux relationship → canonical lux value → destination-unit relationship

Supported inputs

Precision and limits

Unit convention

Illuminance describes luminous flux incident per area; it is not luminance or total lumens.

Precision

Definitions and exact conventional factors are retained internally where available. Display formatting uses up to 12 significant digits; very large or small results use scientific notation. Do not treat displayed digits as measurement accuracy beyond the source value.

Quantity boundary

This page converts illuminance. It does not infer a different physical quantity, material property, environmental condition, exchange rate, calendar rule, or regulatory value needed to make a cross-quantity conversion.

Privacy

Entered values and converted results stay in this browser and are not sent to analytics or third parties.

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