Log value is a measurement used to describe HIV and expresses the viral load values as a power of ten (written log10). The scale is used because large changes can only be captured on graphs or diagrams by using a log scale. This turns large numbers of copies/mL into ‘manageable’ figures.

Table: HIV RNA viral load log value–number conversion

Log10 copies/mL
7 10,000,000
6.9 7,943,282
6.8 6,309,573
6.7 5,011,872
6.6 3,981,072
6.5 3,162,278
6.4 2,511,886
6.3 1,995,262
6.2 1,584,893
6.1 1,258,925
Log10 copies/mL
6 1,000,000
5.9 794,328
5.8 630,957
5.7 501,187
5.6 398,107
5.5 316,228
5.4 251,189
5.3 199,526
5.2 158,489
5.1 125,893
Log10 copies/mL
5 100,000
4.9 79,433
4.8 63,096
4.7 50,119
4.6 39,811
4.5 31,623
4.4 25,119
4.3 19,953
4.2 15,849
4.1 12,589
Log10 copies/mL
4 10,000
3.9 7,943
3.8 6,310
3.7 5,012
3.6 3,981
3.5 3,162
3.4 2,512
3.3 1,995
3.2 1,585
3.1 1,259
Log10 copies/mL
3 1,000
2.9 794
2.8 631
2.7 501
2.6 398
2.5 316
2.4 251
2.3 200
2.2 158
2.1 126
Log10 copies/mL
2 100
1.9 79
1.8 63
1.7 50
1.6 40
1.5 32
1.4 25
1.3 20
1.2 16
1.1 13
Log10 copies/mL
1 10
0.9 8
0.8 6
0.7 5
0.6 4
0.5 3
0.4 3
0.3 2
0.2 2
0.1 1

Last updated: 22 July 2009.