diff --git a/aos/common/commonmath.h b/aos/common/commonmath.h
index f9337b2..acbcb1c 100644
--- a/aos/common/commonmath.h
+++ b/aos/common/commonmath.h
@@ -1,6 +1,8 @@
 #ifndef AOS_COMMON_MATH_H_
 #define AOS_COMMON_MATH_H_
 
+#include <cmath>
+
 namespace aos {
 
 // Clips a value so that it is in [min, max]
@@ -22,6 +24,20 @@
   }
 }
 
+// Adds deadband to provided value.  deadband is the region close to the origin
+// to add the deadband to, and max is the maximum input value used to re-scale
+// the output after adding the deadband.
+static inline double Deadband(double value, const double deadband,
+                              const double max) {
+  if (::std::abs(value) < deadband) {
+    value = 0.0;
+  } else if (value > 0.0) {
+    value = (value - deadband) / (max - deadband);
+  } else {
+    value = (value + deadband) / (max - deadband);
+  }
+  return value;
+}
 }  // namespace aos
 
 #endif  // AOS_COMMON_MATH_H_