diff --git a/usr.bin/cksum/cksum.1 b/usr.bin/cksum/cksum.1
--- a/usr.bin/cksum/cksum.1
+++ b/usr.bin/cksum/cksum.1
@@ -149,6 +149,20 @@
 .Ed
 .Sh EXIT STATUS
 .Ex -std cksum sum
+.Sh EXAMPLES
+Compute the checksum for all available algorithms.
+Notice the difference in the size representation (in bytes for algorithm 1 and 2
+and in blocks for 3 and the default algorithm):
+.Bd -literal -offset indent
+$ echo "hello" | cksum
+3015617425 6
+$ echo "hello" | cksum -o 1
+36979 1
+$ echo "hello" | cksum -o 2
+542 1
+$ echo "hello" | cksum -o 3
+909783072 6
+.Ed
 .Sh SEE ALSO
 .Xr md5 1
 .Pp