diff --git a/extra/math/extras/extras-tests.factor b/extra/math/extras/extras-tests.factor
index 6a93f2809e..4219c1df1f 100644
--- a/extra/math/extras/extras-tests.factor
+++ b/extra/math/extras/extras-tests.factor
@@ -89,3 +89,17 @@ IN: math.extras.test
 [ 2 ] [ { 1 1 2 2 2 } majority ] unit-test
 [ 3 ] [ { 1 2 3 1 2 3 1 2 3 3 } majority ] unit-test
 { CHAR: C } [ "AAACCBBCCCBCC" majority ] unit-test
+
+[ -5 ] [ -4-3/5 round-to-even ] unit-test
+[ -4 ] [ -4-1/2 round-to-even ] unit-test
+[ -4 ] [ -4-2/5 round-to-even ] unit-test
+[ 5 ] [ 4+3/5 round-to-even ] unit-test
+[ 4 ] [ 4+1/2 round-to-even ] unit-test
+[ 4 ] [ 4+2/5 round-to-even ] unit-test
+
+[ -5.0 ] [ -4.6 round-to-even ] unit-test
+[ -4.0 ] [ -4.5 round-to-even ] unit-test
+[ -4.0 ] [ -4.4 round-to-even ] unit-test
+[ 5.0 ] [ 4.6 round-to-even ] unit-test
+[ 4.0 ] [ 4.5 round-to-even ] unit-test
+[ 4.0 ] [ 4.4 round-to-even ] unit-test
diff --git a/extra/math/extras/extras.factor b/extra/math/extras/extras.factor
index 41fc59949c..b2b7fc313e 100644
--- a/extra/math/extras/extras.factor
+++ b/extra/math/extras/extras.factor
@@ -238,3 +238,17 @@ PRIVATE>
 
 : compression-dissimilarity ( a b -- n )
     compression-lengths + / ;
+
+GENERIC: round-to-even ( x -- y )
+
+M: integer round-to-even ; inline
+
+M: ratio round-to-even
+    >fraction [ /mod abs 2 * ] keep > [ dup 0 < -1 1 ? + ] when ;
+
+M: float round-to-even
+    dup 0 > [
+        dup 0x1p52 <= [ 0x1p52 + 0x1p52 - ] when
+    ] [
+        dup -0x1p52 >= [ 0x1p52 - 0x1p52 + ] when
+    ] if ;