How many lux are in one phot?

One phot equals 10,000 lx. The formula is lx = ph × 10,000.

How do I convert phots to lux?

Multiply the value in phots by 10,000. For example, 100 × 10,000 = 1,000,000 — so 100 ph = 1,000,000 lx.

Pair · linear · factor 10,000

phots to lux

phlx

Active unit

phots · ≈ 1,000,000 lx (base)

All units

3 results

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phphot100

How we calculated this

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Frequently asked questions

An emerald lamp casting a cone of light onto a desktop overlaid with an inverse-square-law grid, against a cosmic nebula in violet and magenta

Illuminance

Lumens are not lux — why a desk needs 500 lux

A light-bulb box shouts “800 lumens,” “1600 lumens” — and it feels obvious that a bigger number means a brighter room. It is a trap. Whether you see well is decided by the lux: how much of that emitted light actually lands on your desk. This is the story of illuminance — the inverse-square law, why a full moon gives a quarter of a lux yet still lets you walk at night, and why the office standard is exactly 500 lux.

13 min