diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,9 @@
 
 # CHANGELOG
 
+## 0.1.2
+### Added KnownPeano
+
 ## 0.1.1
 ### Fixed
 * Compilable with ghc-8.0.1
diff --git a/example/Main.hs b/example/Main.hs
--- a/example/Main.hs
+++ b/example/Main.hs
@@ -37,4 +37,5 @@
   print $ prefixConstr p2
   print $ prefixConstr p3
   print $ uniqConstr p2
+  print $ peanoVal (Proxy :: Proxy (FromNat 100))
   -- print $ uniqConstr p3 -- < ElementIsNotUniqInList Int '[Int, Bool, Int]
diff --git a/src/TypeFun/Data/Peano.hs b/src/TypeFun/Data/Peano.hs
--- a/src/TypeFun/Data/Peano.hs
+++ b/src/TypeFun/Data/Peano.hs
@@ -1,5 +1,6 @@
 module TypeFun.Data.Peano
   ( N(..)
+  , KnownPeano(..)
   , ToNat
   , FromNat
   , (:+:)
@@ -7,13 +8,23 @@
   , (:*:)
   ) where
 
-import Data.Typeable
-import GHC.Generics (Generic)
-import GHC.TypeLits
+import           Data.Typeable
+import           GHC.Generics  (Generic)
+import           GHC.TypeLits
 
 data N = Z | S N
          deriving ( Eq, Ord, Read, Show
                   , Generic, Typeable )
+
+-- | @since 0.1.2
+class KnownPeano (p :: N) where
+  peanoVal :: proxy p -> Integer
+
+instance KnownPeano Z where
+  peanoVal _ = 0
+
+instance (KnownPeano n) => KnownPeano (S n) where
+  peanoVal _ = succ $ peanoVal (Proxy :: Proxy n)
 
 type family ToNat (a :: N) :: Nat where
   ToNat Z = 0
diff --git a/type-fun.cabal b/type-fun.cabal
--- a/type-fun.cabal
+++ b/type-fun.cabal
@@ -1,5 +1,5 @@
 name:                type-fun
-version:             0.1.1
+version:             0.1.2
 synopsis:            Collection of widely reimplemented type families
 license:             BSD3
 license-file:        LICENSE