To answer this question, you need to consider the reason why you are interested in using a donut pillow. There are different firmness options on the market. Some may be appropriate for very specific scenarios, whereas others are more universal for various needs. Make sure you consider whether you simply need a donut pillow to support you while sitting at work, or have a medical reason for the cushion. A denser pillow may be a good choice when you need to reduce the pressure that a chair puts on your pelvis but may feel somewhat uncomfortable for people who simply need to soften up the surface they sit on. Keep in mind that many of these pillows offer a responsive structure, which can help to provide a more conforming shape for added comfort while delivering a medium-firm density.