Use this Calculator to calculate HDPE pipe thickness and cost as per the NS40:2079 Nepal Bureau of Standards.
The above calculator uses the material type PE100 (density 940Kg/m3), which is the most common type of HDPE used commercially.
To know the thickness of other PE pipes and to get data for pipe thickness directly. You can directly look at the table below (Table 4 of NS40:2079 Standards)
To know more about the HDPE pipe standards in Nepal and know the old vs new HDPE pipe code. See Article Below: