diff --git a/include_/vint.h b/include_/vint.h
index 3a8f4cc..49f7a06 100644
--- a/include_/vint.h
+++ b/include_/vint.h
@@ -1,4 +1,8 @@
 //-- "Integer Compression" variable byte (scalar TurboVByte+ SIMD TurboByte) ---------------------------------------------------------------
+#define V8PAYLOAD(_n_, _usize_) (((_n_)*(_usize_/16)+7)/8)
+#define V8BOUND_(_n_, _usize_) (V8PAYLOAD(_n_, _usize_)+ (_n_)*(_usize_/8))
+#define V8BOUND16(_n_) V8BOUND_(_n_, 16)
+#define V8BOUND32(_n_) V8BOUND_(_n_, 32)
 
 #ifdef __cplusplus
 extern "C" {