Percent to ratio conversion

Cleaning labels mix the two. 1 % v/v and 1:100 are NOT exactly the same. 1 % = 1 part in 100 total = 1:99 (1 part to 99 parts water).

§ 1Conversion table

% v/vRatio (1 : X)Cleaning-label shorthand
0.1 %1 : 999≈ 1:1000
0.5 %1 : 199≈ 1:200
1 %1 : 99≈ 1:100
2 %1 : 49≈ 1:50
5 %1 : 19≈ 1:20
10 %1 : 9≈ 1:10
20 %1 : 4≈ 1:5
25 %1 : 3≈ 1:4
50 %1 : 1≈ 1:2

The shorthand column is what label printers usually round to. The middle column is the exact arithmetic.

§ 2Related