I use an accurate measuring jug, put pretty much what you need in, and then start the engine, get the oil up to temp, turn off and let settle for a few mins and check the dipstick. Then just slowly add more oil to bring up to the correct level. If you put too much in as someone mentioned above. I think the best way would be to let the oil go cold, and then slowly take the drain plug out and drain some out into a clean jug. You may make a bit of a mess, but you will have fresh oil in the jug, and if you do accidently take too much out, just add it again. Best way Ive found to do my changes and get the correct amount of oil in the car. If you do this, you will know that you have the right amount of oil in for 'your' car.