diff --git a/sigrok.h b/sigrok.h
index 5606a1e5..ebbfcb89 100644
--- a/sigrok.h
+++ b/sigrok.h
@@ -59,6 +59,8 @@
 #define MHZ(n) ((n) * 1000000)
 #define GHZ(n) ((n) * 1000000000)
 
+#define HZ_TO_NS(n) (1000000000 / (n))
+
 #ifndef ARRAY_SIZE
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
 #endif