Listed below are free OEE calculators available to help with OEE calculation. These range from simple spreadsheets to calculate OEE for a single machine to demonstration and fully capability software packages.
Plantrun have a spreadsheet for OEE calculation on up to 10 machines OEE Calculator
Vergence Analytics offer free spreadsheet templates including cost weighted and multi machine OEE Templates
Capstone Metrics offer a demonstration version of their OEE software