Monitor CPU Usage using snmp

[diopter]

i am using snmp to capture data from my server, and recently i am stuck in how to monitor cpu usage in percentage.

i able to capture below value with oid:

CPU Usage - Idle .1.3.6.1.4.1.2021.11.53.0
CPU Usage - System .1.3.6.1.4.1.2021.11.52.0
CPU Usage - User .1.3.6.1.4.1.2021.11.50.0

and the return value are like 1443115296, very big number..

i would like to know the what is this number represent and how to convert it to percentage..

please help.

thx