Try the easy-to-use Perfect Fit Selector tool for help finding the correct sized PrivaScreen™ Blackout Privacy Filter for your screen:
http://apps.fellowes.com/screenselector/
Or manually measure your screen following these steps:
1. Start in the lower left corner of your screen and measure to the upper right corner. This will determine the diagonal measurement of your screen. Do not include any plastic bevel or frame, just the functional part of the screen that displays graphics.
2. Once you've determined the diagonal measurement, also measure the width and height in the same manner, measuring only the active portion of the screen.
3. All three dimensions (Diagonal, Width and Height) are needed to ensure you choose the proper privacy filter size. It is possible that two screens share the same diagonal measurement, but have different heights and widths. These two screens would have different aspect ratios. The aspect ratio defines the proportion of the height and the width and is expressed by two numbers separated by a colon. It is important to review all of the measurements, including the aspect ratio, before purchasing a blackout filter.