Typical figures might be Grade 5 = ISO(R) 40 to 45; Grade 4 = ISO(R) 60 to 70; Grade 3 = ISO(R) 80 to 90; Grade 2 = ISO(R) 100 to 110; Grade 1 = ISO(R) 120 to 130; Grade 0 = ISO(R) 140 to 150; Grade 00 = ISO(R) 160 to 180.

So I get about grade 4 to 00. Again, I'm not using a reflection sensitometer. I'm just counting the number of gray stripes printed by the 21-step scale (leaving out the one that is 'just off white' and 'just off black') then multiplying by 15 to get an estimate of my ISO R contrast grade.