Do the Americans list it the other way around? as I've seen some things listed as 10:1 etc.
Example citrus pre wash in the UK:
1:6 heavy soiled
1:10 light soiled
So all I do is divide my 1000ml container by the total amount of parts and use the first number for the chemical and the second for the water. So for a 1:6 mix 1000ml/7 = 142.85 which gives me round figures of 143ml citrus pre wash and 857ml of water.
Example citrus pre wash in the UK:
1:6 heavy soiled
1:10 light soiled
So all I do is divide my 1000ml container by the total amount of parts and use the first number for the chemical and the second for the water. So for a 1:6 mix 1000ml/7 = 142.85 which gives me round figures of 143ml citrus pre wash and 857ml of water.