18 LOC approach according to Bloggs:
350ft per nm/3.28°.
21 7580
20 7230
19 6880
18 6530
17 6180
16 5830
15 5480
14 5130
13 4780
12 4430
11 4080
10 3730
9 3380
8 3030
7 2680
6 2330 (limit 2300)
5 1980
4 1630
3.3 1385 (MDA)
3 1280
2 930
1 580
Get on it, stay on it. End of story. Too hard to work out? Get the FAA to put it on your charts.