Music Intervals

I have spent weeks getting in a twist where music intervals are concerned but I think I've cracked it now. Below is a table of intervals. NB 4ths 5ths 8ths have no Major or Minor.

Key: 

Dim = Diminished
Min = Minor
Maj = Major
Perf = Perfect
Aug = Augmented

When counting intervals (major 2nd, minor 3rd etc) Start finding out what the interval is first. To find that count each note. e.g. C to E would be a 3rd, you count your starting note (ie C = 1, D = 2, E = 3) BUT to find out whether the note is Diminished, Major, Minor etc you count the semitones! This time C# is counted as the first step. So count:
1= C# 2 = D 3 = D# 4 = E Now look on the chart under 3rd and find the number 4 - 4 steps makes the interval a Major 3rd. 
This works for any scale and it works for transposing too. Even if you have a scale with a lot of sharps (or flats) e.g. F# Major has 6# - if you wanted to find the interval between F# and D# = then it would be a 6th (don't worry about the #s - just count F-D [even if the note is F#- D natural still count it as F - D) Let's go back to F# - D# = Now count the semitones, remember start on the next semitone from F#, which is G. It's 9 steps therefore the Interval is a Major 6th. Now if we were looking at F# - D natural this interval would be - Minor 6th because it's only 8 steps. F# - Db would be a diminished 6th as there are only 7 steps! 

2nd		3rd		4th		5th		6th		7th		8th
Dim	0	Dim	2	Dim	4	Dim	6	Dim	7	Dim	9	Dim	11
Min	1	Min	3	Perf	5	Perf	7	Min	8	Min	10	Perf	12
Maj	2	Maj	4	Aug	6	Aug	8	Maj	9	Maj	11	Aug	13
Aug	3	Aug	5					Aug	10	Aug	12