diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Revision history for scientific-notation
 
+## 0.1.2.0 -- 2020-05-01
+
+* Add `builderUtf8`.
+
 ## 0.1.1.0 -- 2019-11-06
 
 * Add `withExposed`.
diff --git a/scientific-notation.cabal b/scientific-notation.cabal
--- a/scientific-notation.cabal
+++ b/scientific-notation.cabal
@@ -1,6 +1,6 @@
 cabal-version: 2.2
 name: scientific-notation
-version: 0.1.1.0
+version: 0.1.2.0
 synopsis: Scientific notation intended for tokenization
 description:
   This library provides a type used to represent a number in
@@ -49,7 +49,9 @@
   exposed-modules: Data.Number.Scientific
   build-depends:
     , base >=4.12 && <5
+    , bytebuild >=0.3.5 && <0.4
     , bytesmith >=0.3 && <0.4
+    , natural-arithmetic >=0.1.1 && <0.2
   hs-source-dirs: src
   ghc-options: -O2 -Wall
   default-language: Haskell2010
@@ -61,13 +63,14 @@
   main-is: Main.hs
   ghc-options: -Wall -O2
   build-depends:
-    , QuickCheck >=2.13.1 && <2.14
+    , QuickCheck >=2.13.1
     , base >=4.12.0.0 && <5
+    , bytebuild
     , byteslice
     , bytestring
     , scientific-notation
-    , tasty >=1.2.3 && <1.3
-    , tasty-hunit >=0.10.0.2 && <0.11
+    , tasty >=1.2.3
+    , tasty-hunit >=0.10.0.2
     , tasty-quickcheck
     , primitive
     , bytesmith
diff --git a/src/Data/Number/Scientific.hs b/src/Data/Number/Scientific.hs
--- a/src/Data/Number/Scientific.hs
+++ b/src/Data/Number/Scientific.hs
@@ -33,6 +33,8 @@
   , parserUnsignedUtf8Bytes#
   , parserNegatedUtf8Bytes#
   , parserNegatedTrailingUtf8Bytes#
+    -- * Encode
+  , builderUtf8
   ) where
 
 import Prelude hiding (negate)
@@ -40,10 +42,14 @@
 import GHC.Exts (Int#,Word#,Int(I#),(+#))
 import GHC.Word (Word(W#),Word8(W8#),Word16(W16#),Word32(W32#),Word64(W64#))
 import GHC.Int (Int64(I64#),Int32(I32#))
+import Data.Bytes.Builder (Builder)
 import Data.Bytes.Parser.Unsafe (Parser(..))
 import Data.Fixed (Fixed(MkFixed),HasResolution)
 
+import qualified Arithmetic.Nat as Nat
 import qualified Data.Fixed as Fixed
+import qualified Data.Bytes.Builder as Builder
+import qualified Data.Bytes.Builder.Bounded as BB
 import qualified Data.Bytes.Parser as Parser
 import qualified Data.Bytes.Parser.Latin as Latin
 import qualified Data.Bytes.Parser.Unsafe as Unsafe
@@ -848,3 +854,19 @@
       (# | (# y, b, c #) #) ->
         runParser (g y) (# arr, b, c #) s1
   )
+
+builderUtf8 :: Scientific -> Builder
+builderUtf8 (Scientific coeff e big)
+  | e == 0 = Builder.intDec coeff
+  | e == minBound = let LargeScientific coeff' e' = big in
+      Builder.integerDec coeff'
+      <>
+      Builder.ascii 'e'
+      <>
+      Builder.integerDec e'
+  | otherwise = Builder.fromBounded Nat.constant $
+      BB.intDec coeff
+      `BB.append`
+      BB.ascii 'e'
+      `BB.append`
+      BB.intDec e