Distance from Duncanville, TX to Houston, TX. The total distance from Duncanville, TX to Houston, TX is 219 miles. This is equivalent to 352 kilometers or 190 nautical miles. Your trip begins in Duncanville, Texas. It ends in Houston, Texas. Your flight direction from Duncanville, TX to Houston, TX is Southeast (155 degrees from North). The distance calculator helps you figure out how far it is to fly from Duncanville, TX to Houston, TX. It does this by computing the straight line flying distance (as the crow flies).