diff --git a/include/sigar_private.h b/include/sigar_private.h
index 4890dcbf..ae49df71 100644
--- a/include/sigar_private.h
+++ b/include/sigar_private.h
@@ -63,6 +63,9 @@
 #define SIGAR_SEC2NANO(s) \
     ((sigar_uint64_t)(s) * (sigar_uint64_t)1000000000)
 
+/* cpu ticks to seconds */
+#define SIGAR_TICK2SEC(s) (s / sigar->ticks)
+
 #define SIGAR_LAST_PROC_EXPIRE 2
 
 #define SIGAR_FS_MAX 10