Bit mask first 2 bits of 16 bits for accelerometer
Since it won't convert to two's complement if the sign bit is the 14 bit instead of the 16th, it would be easier to just shift the value left by 2. So

int bresult= result&lt;&lt;2;


Since &lt;&lt;2 is the same as *4 the result will be 4 times as high. So you need to divide the result by 4. Since you already have to multiply by 0.025 (or divide by 40), you end up having to multiply by 0.00625 (or divide by 160).