diff --git a/libraries/AP_Compass/CompassCalibrator.cpp b/libraries/AP_Compass/CompassCalibrator.cpp
index 0bb841cc28..9b39dab91d 100644
--- a/libraries/AP_Compass/CompassCalibrator.cpp
+++ b/libraries/AP_Compass/CompassCalibrator.cpp
@@ -686,8 +686,8 @@ uint16_t CompassCalibrator::get_random(void)
 //////////// CompassSample public interface //////////////
 //////////////////////////////////////////////////////////
 
-#define COMPASS_CAL_SAMPLE_SCALE_TO_FIXED(__X) ((int16_t)constrain_float(roundf(__X*16.0f), INT16_MIN, INT16_MAX))
-#define COMPASS_CAL_SAMPLE_SCALE_TO_FLOAT(__X) (__X/16.0f)
+#define COMPASS_CAL_SAMPLE_SCALE_TO_FIXED(__X) ((int16_t)constrain_float(roundf(__X*8.0f), INT16_MIN, INT16_MAX))
+#define COMPASS_CAL_SAMPLE_SCALE_TO_FLOAT(__X) (__X/8.0f)
 
 Vector3f CompassCalibrator::CompassSample::get() const {
     return Vector3f(COMPASS_CAL_SAMPLE_SCALE_TO_FLOAT(x),