lb vs lux, What's the Difference?

Which to use

“lb” is a symbol and “lux” is a noun - they look or sound alike but fill different roles in a sentence.

#22,921
“lb” frequency rank: #18,246
“lux” frequency rank: 41167
confusion score

Side-by-Side Comparison

Feature	lb	lux
Definition	Symbole de la livre (pound), unité de mesure de masse anglo-saxonne. Cette livre est ordinairement dans le système avoir-du-poids ; il y a aussi une livre apothicaire (apothecary pound ou troy pound) — les symboles respectifs sont lb av et lb t ou lb Tr. La livre française, elle, avait pour symbole lp.	Unité de mesure d’éclairement lumineux du Système international, définie comme lumen par mètre carré, dont le symbole est lx.

Where the spellings diverge

Shared letters are muted; the letters that actually set lb and lux apart are highlighted. They share 1 letter in sequence, which is exactly why the eye skips the difference.

2 ch

3 ch

lux

Spelling & Dictionary Insight

lb and lux form a confusable pair in the French index, two distinct headwords that are easily confused because they look alike, sound alike, or both. They differ by 1 letter(s) in length - close enough that the eye skips over the difference, far enough that meaning fully diverges. Our composite confusion score for this pair is 41167, derived from the frequency rank of both members and their visual similarity.

lb is recorded at frequency rank #22,921, classified as asymbol. lux is at rank #18,246, tagged as anoun, pronounced \lyks\.

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 41167, this pair ranks #235,120 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Frequency comparison

lb#22,921

lux#18,246

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "lb" and "lux" be used interchangeably?

No, "lb" and "lux" have distinct meanings and cannot be swapped without changing the meaning of a sentence. Understanding the specific definition and context for each word is essential for correct usage.

Remembering lb vs lux

The fastest way to pick the right one every time.

Check the role first: if you need a symbol, it's “lb”; for a noun, it's “lux”.
See each word in full, definition, IPA, etymology and its other confusables. Full “lb” entry
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