diff --git a/doc/Makefile.in b/doc/Makefile.in
index ad9f37b..b099b9e 100644
--- a/doc/Makefile.in
+++ b/doc/Makefile.in
@@ -30,13 +30,17 @@ OBJECTS=ck_ht_allocator_set$(GZIP_SUFFIX) 		\
 	ck_bitmap_init$(GZIP_SUFFIX)			\
 	ck_bitmap_reset_mpmc$(GZIP_SUFFIX)		\
 	ck_bitmap_set_mpmc$(GZIP_SUFFIX)		\
-	ck_bitmap_test$(GZIP_SUFFIX)
+	ck_bitmap_test$(GZIP_SUFFIX)			\
+	ck_bitmap_base$(GZIP_SUFFIX)
 
 all: $(OBJECTS)
 
 ck_bitmap_init$(GZIP_SUFFIX): ck_bitmap_init
 	$(GZIP) ck_bitmap_init > ck_bitmap_init$(GZIP_SUFFIX)
 
+ck_bitmap_base$(GZIP_SUFFIX): ck_bitmap_base
+	$(GZIP) ck_bitmap_base > ck_bitmap_base$(GZIP_SUFFIX)
+
 ck_bitmap_test$(GZIP_SUFFIX): ck_bitmap_test
 	$(GZIP) ck_bitmap_test > ck_bitmap_test$(GZIP_SUFFIX)
 
diff --git a/doc/ck_bitmap_base b/doc/ck_bitmap_base
new file mode 100644
index 0000000..dffc553
--- /dev/null
+++ b/doc/ck_bitmap_base
@@ -0,0 +1,58 @@
+.\"
+.\" Copyright 2012 Samy Al Bahra.
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"
+.Dd April 22, 2012
+.Dt CK_BITMAP_BASE 3
+.Sh NAME
+.Nm ck_bitmap_base
+.Nd determine the size bit array in bytes
+.Sh LIBRARY
+Concurrency Kit (libck, \-lck)
+.Sh SYNOPSIS
+.In ck_bitmap.h
+.Ft unsigned int
+.Fn ck_bitmap_base "unsigned int n_bits"
+.Sh DESCRIPTION
+The 
+.Fn ck_bitmap_base
+function returns the number of bytes that would be used
+to store the number of bits specified by
+.Fa n_bits .
+.Sh RETURN VALUES
+This function returns a non-zero value that is guaranteed to
+be a multiple of
+.Dv sizeof(CK_BITMAP_WORD) .
+.Sh SEE ALSO
+.Xr ck_bitmap_size 3 ,
+.Xr ck_bitmap_init 3 ,
+.Xr ck_bitmap_set_mpmc 3 ,
+.Xr ck_bitmap_reset_mpmc 3 ,
+.Xr ck_bitmap_test 3 ,
+.Xr ck_bitmap_clear 3 ,
+.Xr ck_bitmap_bits 3 ,
+.Xr ck_bitmap_buffer 3
+.Pp
+Additional information available at http://concurrencykit.org/