All Unit Conversions

Light Measurement Conversion Chart

Quick-reference light measurement conversion chart. The tables below compare the most common units side by side. Download the free PDF for offline and printable use.

What is light (luminous units)?

Light measurements quantify luminous flux (lumens), illuminance (lux), and luminous intensity (candela). One lux equals one lumen per square meter.

Key conversions

  • 1 lux (lx) = 1 lumen per square meter (lm/m²)
  • 1 foot-candle ≈ 10.764 lux
  • Luminous intensity is measured in candela (cd)
  • 1 lumen = 1 cd·sr (candela steradian)

Standards and method

Values are calculated from the shared conversion-factor library. Exact defined relationships are preserved; displayed results are rounded only for readability.

Maintained by Miguel Coelho. Updated . See our editorial policy.

Preview of the printable Light Measurement Conversion Chart

Printable light measurement conversion chart

Lux, foot-candles, nits and foot-lamberts, with recommended light levels. Includes the exact definition, formulas, a worked example and sources. Conversion values are checked against the defining constants, and reference data is cited to its source, before the PDF is published.

Free to print, share and use in teaching materials with attribution (CC BY 4.0).

Download A4 PDFDownload US Letter PDF
Download the light measurement conversion chart PDFDownload this chart as CSVDownload this chart as JSONOpen the full light measurement converter →

Light Measurement Conversion Table

Illuminance

Illuminance conversion factors
Unitper 1 lx
Lux (lx)1 lx
Foot Candle (fc)0.092903 fc
Phot (ph)0.0001 ph

Luminance

Luminance conversion factors
Unitper 1 cd/m²
Candela per Square Meter (cd/m²)1 cd/m²
Foot Lambert (fL)0.291864 fL
Lambert (L)0.000314159 L
Stilb (sb)0.0001 sb

Luminous energy

Luminous energy conversion factors
Unitper 1 lm⋅s
Lumen Second (lm⋅s)1 lm⋅s
Lumen Minute (lm⋅min)0.0166667 lm⋅min
Lumen Hour (lm⋅h)0.000277778 lm⋅h

Luminous intensity

Luminous intensity conversion factors
Unitper 1 cd
Candela (cd)1 cd
Hefnerkerze (HK)1.10742 HK

Values are calculated from the shared conversion-factor library. Exact defined relationships are preserved; displayed results are rounded only for readability.

Full light measurement conversion chart

Lux, foot-candles, nits and foot-lamberts, with recommended light levels. These are the same tables as the printable PDF. For: Lighting designers, photographers, facility managers and display engineers.

Exact definition
1 fc = 1 lm/ft² = 10.763 910 4 lx; 1 fL = 3.426 259 cd/m² (exact)
Formula
lx = fc × 10.7639
Reverse
fc = lx ÷ 10.7639
Worked example
500 lx (office desk) = 46.45 fc
Rounding
Values are rounded to 2 decimal places. Recommended levels are maintained illuminance on the task area.

Lux to foot-candles

Lux to foot-candles (part 1)
Lux (lx)Foot-candles (fc)
10.09
50.46
100.93
201.86
504.65
756.97
1009.29
15013.94
20018.58
30027.87
Lux to foot-candles (part 2)
Lux (lx)Foot-candles (fc)
50046.45
75069.68
1,00092.90
1,500139.35
2,000185.81
5,000464.52
10,000929.03
20,0001,858.06
50,0004,645.15
100,0009,290.30

Display brightness: nits to foot-lamberts

Display brightness: nits to foot-lamberts (part 1)
Nits (cd/m²)Foot-lamberts (fL)
5014.59
10029.19
20058.37
25072.97
30087.56
400116.75
500145.93
Display brightness: nits to foot-lamberts (part 2)
Nits (cd/m²)Foot-lamberts (fL)
600175.12
800233.49
1,000291.86
1,500437.80
2,000583.73
4,0001,167.45
10,0002,918.64

LED and incandescent bulb equivalents (approximate)

LED and incandescent bulb equivalents (approximate)
Old incandescent bulbMinimum light outputTypical LED
40 W450 lm4–6 W
60 W800 lm8–10 W
75 W1,100 lm11–13 W
100 W1,600 lm15–18 W

Sources for this chart

Conversion values on this sheet are generated by the AllUnitConversions conversion library and automatically checked against the exact definitions above before the PDF is produced; reference tables are taken from the sources listed.

  • NIST Special Publication 811 — Guide for the Use of the International System of Units
  • EN 12464-1 — Light and lighting — lighting of indoor work places (maintained illuminance)
  • US FTC Lighting Facts — Lumen equivalents for replacing incandescent bulbs

Related Converters & Charts

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Suggested citation for reports, coursework and slides.

Coelho, M. (2026). Light Measurement Conversion Chart (Edition 2.0). All Unit Conversions. https://allunitconversions.com/light-conversion-chart

Light Measurement Conversion Chart FAQs

Common questions about the light measurement conversion chart.

What does this light measurement conversion chart include?

It lists the most common light measurement units side by side with their conversion factors, plus a free printable PDF you can download for offline reference.

What exact definition is this light measurement chart based on?

1 fc = 1 lm/ft² = 10.763 910 4 lx; 1 fL = 3.426 259 cd/m² (exact). Formula: lx = fc × 10.7639. Values are rounded to 2 decimal places. Recommended levels are maintained illuminance on the task area.

Can I download this chart as a PDF, CSV, or JSON?

Yes. Use the Download A4 PDF or US Letter PDF buttons for a printable version, or download the same tables as CSV or JSON from the links on this page.