adxl345 TO DEGREES

I wonder if someone knows how to convert the reading from adxl345 to degrees

BELOW IS MY CODE
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_ADXL345_U.h>

/* Assign a unique ID to this sensor at the same time */
Adafruit_ADXL345_Unified accel = Adafruit_ADXL345_Unified(12345);

void displaySensorDetails(void)
{
sensor_t sensor;
accel.getSensor(&sensor);
Serial.println("------------------------------------");
Serial.print ("Sensor: "); Serial.println(sensor.name);
Serial.print (“Driver Ver: “); Serial.println(sensor.version);
Serial.print (“Unique ID: “); Serial.println(sensor.sensor_id);
Serial.print (“Max Value: “); Serial.print(sensor.max_value); Serial.println(” m/s^2”);
Serial.print (“Min Value: “); Serial.print(sensor.min_value); Serial.println(” m/s^2”);
Serial.print (“Resolution: “); Serial.print(sensor.resolution); Serial.println(” m/s^2”);
Serial.println(”------------------------------------”);
Serial.println(””);
delay(500);
}

void displayDataRate(void)
{
Serial.print ("Data Rate: ");

switch(accel.getDataRate())
{
case ADXL345_DATARATE_3200_HZ:
Serial.print ("3200 ");
break;
case ADXL345_DATARATE_1600_HZ:
Serial.print ("1600 ");
break;
case ADXL345_DATARATE_800_HZ:
Serial.print ("800 ");
break;
case ADXL345_DATARATE_400_HZ:
Serial.print ("400 ");
break;
case ADXL345_DATARATE_200_HZ:
Serial.print ("200 ");
break;
case ADXL345_DATARATE_100_HZ:
Serial.print ("100 ");
break;
case ADXL345_DATARATE_50_HZ:
Serial.print ("50 ");
break;
case ADXL345_DATARATE_25_HZ:
Serial.print ("25 ");
break;
case ADXL345_DATARATE_12_5_HZ:
Serial.print ("12.5 ");
break;
case ADXL345_DATARATE_6_25HZ:
Serial.print ("6.25 ");
break;
case ADXL345_DATARATE_3_13_HZ:
Serial.print ("3.13 ");
break;
case ADXL345_DATARATE_1_56_HZ:
Serial.print ("1.56 ");
break;
case ADXL345_DATARATE_0_78_HZ:
Serial.print ("0.78 ");
break;
case ADXL345_DATARATE_0_39_HZ:
Serial.print ("0.39 ");
break;
case ADXL345_DATARATE_0_20_HZ:
Serial.print ("0.20 ");
break;
case ADXL345_DATARATE_0_10_HZ:
Serial.print (“0.10 “);
break;
default:
Serial.print (”??? “);
break;
}
Serial.println(” Hz”);
}

void displayRange(void)
{
Serial.print ("Range: +/- ");

switch(accel.getRange())
{
case ADXL345_RANGE_16_G:
Serial.print ("16 ");
break;
case ADXL345_RANGE_8_G:
Serial.print ("8 ");
break;
case ADXL345_RANGE_4_G:
Serial.print ("4 ");
break;
case ADXL345_RANGE_2_G:
Serial.print (“2 “);
break;
default:
Serial.print (”?? “);
break;
}
Serial.println(” g”);
}

void setup(void)
{
#ifndef ESP8266
while (!Serial); // for Leonardo/Micro/Zero
#endif
Serial.begin(9600);
Serial.println(“Accelerometer Test”); Serial.println("");

/* Initialise the sensor /
if(!accel.begin())
{
/
There was a problem detecting the ADXL345 … check your connections */
Serial.println(“Ooops, no ADXL345 detected … Check your wiring!”);
while(1);
}

/* Set the range to whatever is appropriate for your project */
accel.setRange(ADXL345_RANGE_16_G);
// displaySetRange(ADXL345_RANGE_8_G);
// displaySetRange(ADXL345_RANGE_4_G);
// displaySetRange(ADXL345_RANGE_2_G);

/* Display some basic information on this sensor */
displaySensorDetails();

/* Display additional settings (outside the scope of sensor_t) */
displayDataRate();
displayRange();
Serial.println("");
}

void loop(void)
{
/* Get a new sensor event */
sensors_event_t event;
accel.getEvent(&event);

/* Display the results (acceleration is measured in m/s^2) */
Serial.print("X: “); Serial.print(event.acceleration.x); Serial.print(” ");
Serial.print("Y: “); Serial.print(event.acceleration.y); Serial.print(” ");
Serial.print("Z: “); Serial.print(event.acceleration.z); Serial.print(” ");Serial.println("m/s^2 ");
delay(500);
}

There is no direct correlation acc ←→ angle

The best you can hope for is to measure the tilt of the sensor relative to earth's gravity vector.

Look at this link for details.