This is EIA standard resistance value calculator.The EIA types such as E6, E12, etc. were developed by EIA with the number (6 or 12) being the number of values per decade.

Tolerances
E6 = 20%
E12= 10%
E24 = 5%
E48 = 2%
E96 = 1%
E192 = 0.5%

Tighter tolerances such as 0.25%, 0.5% or 0.05% are available in E192 values from some manufacturers.