How do I pronounce R² as seen in chemistry formulas or maths? I can pronounce it as "R-square" but what other word is there for "square"?

  • I always pronounce R2D2 the way C3PO does.
    – tchrist
    May 18, 2014 at 2:15
  • sorry c3po what? sry im no native english speaker
    – user76468
    May 18, 2014 at 2:18
  • It’s the Lucasian equation.
    – tchrist
    May 18, 2014 at 2:20

4 Answers 4


In this case, if 2 is above R, then it can be termed as:

Superior character or Superscript

Or if the 2 is below R, then it can be termed as :

Inferior character or Subscript.

  • 2
    The OP asked how it's pronounced, not what the technical term for it is.
    – Erik Kowal
    May 18, 2014 at 4:30
  • @ErikKowal read his last sentence... "I can pronounce as R square but what other word for square?"
    – Invoker
    May 18, 2014 at 4:43

Try "R squared", "R raised to the power two", or "R to the power of two".


In chemistry, the number is pronounced as usual. H2O2 is pronounced "H two O two".

In maths, it is different. You need to know what the function of the number is. 2 can be "two", or "squared" or other names.


In mathematics, a common short form of "R to the power of two" is "R to the two" (but not "R to two"). This expression is used for general powers (x^7, 2^6, e^x, etc.), whereas for powers 2 and 3 one usually uses "squared" and "cubed".

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