Use a one-inch movement
Disable pointer acceleration when possible, place a ruler beside the pointer and move in a straight line. Repeat three times in each direction, then average your measurements.
Mouse DPI test: measure sensitivity online
Measure mouse sensitivity and calculate DPI from a known physical movement.
Start the mouse testCalculate mouse DPI from a measured movement
Move the pointer a known physical distance, note the screen pixels travelled, then enter both values.
Estimated DPI800pixels ÷ inches