diff --git a/Adafruit_PWMServoDriver.cpp b/Adafruit_PWMServoDriver.cpp
index 4c614fe..f3170ac 100755
--- a/Adafruit_PWMServoDriver.cpp
+++ b/Adafruit_PWMServoDriver.cpp
@@ -296,24 +296,17 @@ void Adafruit_PWMServoDriver::writeMicroseconds(uint8_t num, uint16_t Microsecon
   double pulselength;
   pulselength = 1000000;   // 1,000,000 us per second
 
-  // Read prescale and convert to frequency
-  double prescale = Adafruit_PWMServoDriver::readPrescale();
-  prescale += 1;
-  uint32_t freq = 25000000; // Chip frequency is 25MHz
-  freq /= prescale;
-  freq /= 4096; // 12 bits of resolution
- 
-  #ifdef ENABLE_DEBUG_OUTPUT
-  Serial.print(freq); Serial.println(" Calculated PCA9685 chip PWM Frequency");
-  #endif
-  
-  pulselength /= freq;   //  us per period from PCA9685 chip PWM Frequency using prescale reverse frequency calc
+  // Read prescale
+  uint16_t prescale = Adafruit_PWMServoDriver::readPrescale();
 
   #ifdef ENABLE_DEBUG_OUTPUT
-  Serial.print(pulselength); Serial.println(" us per period");
+  Serial.print(prescale); Serial.println(" PCA9685 chip prescale");
   #endif
 
-  pulselength /= 4096;  // 12 bits of resolution
+  // Calculate the pulse for PWM based on Equation 1 from the datasheet section 7.3.5
+  prescale += 1;
+  pulselength *= prescale; 
+  pulselength /= FREQUENCY_CALIBRATED;
 
   #ifdef ENABLE_DEBUG_OUTPUT
   Serial.print(pulselength); Serial.println(" us per bit");