diff --git a/exact-pi.cabal b/exact-pi.cabal
--- a/exact-pi.cabal
+++ b/exact-pi.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                exact-pi
-version:             0.1.0.0
+version:             0.1.1.0
 synopsis:            Exact rational multiples of pi (and integer powers of pi)
 description:         Provides an exact representation for rational multiples of pi alongside an approximate representation of all reals.
                      Useful for storing and computing with conversion factors between physical units.
diff --git a/src/Data/ExactPi.hs b/src/Data/ExactPi.hs
--- a/src/Data/ExactPi.hs
+++ b/src/Data/ExactPi.hs
@@ -19,7 +19,8 @@
 (
   ExactPi(..),
   approximateValue,
-  isExactZero
+  isExactZero,
+  isExactOne
 )
 where
 
@@ -41,6 +42,11 @@
 isExactZero :: ExactPi -> Bool
 isExactZero (Exact _ 0) = True
 isExactZero _ = False
+
+-- | Identifies whether an 'ExactPi' is an exact representation of one.
+isExactOne :: ExactPi -> Bool
+isExactOne (Exact 0 1) = True
+isExactOne _ = False
 
 instance Show ExactPi where
   show (Exact z q) | z == 0 = "Exactly " ++ show q