WPI
WPI is the abbreviation of:
- Short use of DWPI (Derwent World Patents Index)
- Whey protein isolate, a dietary supplement created by filtering milk protein
- Whittemore Peterson Institute, performs research into chronic fatigue syndrome
- Wholesale price index, the price of a representative basket of wholesale goods
- Worcester Polytechnic Institute, a private research university in Worcester, Massachusetts, US
- Work Personality Index
- Worker-Communist Party of Iran, a political party
- Whang's Personal Identity, a psychological assessment tool
- Wraps per inch, a measure of thickness of yarn