diff --git a/common/conversions.py b/common/conversions.py
index b02b33c62..62c8debdb 100644
--- a/common/conversions.py
+++ b/common/conversions.py
@@ -11,6 +11,12 @@ class Conversions:
   MS_TO_KNOTS = 1.9438
   KNOTS_TO_MS = 1. / MS_TO_KNOTS
 
+  # Distance
+  METER_TO_FOOT = 3.28084
+  FOOT_TO_METER = 1. / METER_TO_FOOT
+  CM_TO_INCH = 1. / 2.54
+  INCH_TO_CM = 1. / CM_TO_INCH
+
   # Angle
   DEG_TO_RAD = np.pi / 180.
   RAD_TO_DEG = 1. / DEG_TO_RAD
diff --git a/common/util.h b/common/util.h
index 186873ac2..4c67312a4 100644
--- a/common/util.h
+++ b/common/util.h
@@ -36,6 +36,9 @@ const double MS_TO_KPH = 3.6;
 const double MS_TO_MPH = MS_TO_KPH * KM_TO_MILE;
 const double METER_TO_MILE = KM_TO_MILE / 1000.0;
 const double METER_TO_FOOT = 3.28084;
+const double FOOT_TO_METER = 1. / METER_TO_FOOT;
+const double CM_TO_INCH = 1. / 2.54;
+const double INCH_TO_CM = 1. / CM_TO_INCH;
 
 namespace util {