Not sure on the rear but the fronts are 5x7's
6 and 1/2 inches, round speakers on a 2000. Probably same on 2001.
6.5 or 6 1/2 in front and 6 x 9 speakers in back.
6 1/2 front and back
3-1/4 in front 4 x 10 in back
3-1/4 in front 4 x 10 in back
6x9 in the back and 4x6 in the front doors but you can buy an adapter for the front door speakers on eBay to allow you to put larger round 6.25 inch in
5 1/4 for the back doors and 6 1/2 for the front doors. I am not sure about the dash board speakers.
For most civics its the same, 3x2 in the front and 6x9's in the back behind the passengers.
6.5" round speakers in the front and back.
5.5" speakers front and back.
The first three speakers you want to buy are your subwoofer and the 2 left and right front speakers. Next you will want to get the 2 left and right back speaker and then the center front and center back speakers.
front speakers and back speakers are both 6x8 speakers