“Zero gravity” is a memorable name for a supported reclined position—not the absence of gravity and not a clinical treatment. An adjustable base raises both the upper body and legs so the knees sit above or near heart level, distributing contact differently from lying flat.
Where the name came from
The term borrows from neutral-body postures associated with aerospace research. Bed manufacturers use it for a family of similar angles, but there is no single universal setting shared by every model or body.
What the preset button does
Pressing a preset sends the base to stored head and leg heights. On some beds the position can be reprogrammed; on others it is fixed. Mattress thickness, pillow choice and body proportions change how the same deck angles feel.
Comfort uses people can test
- Relaxing without stacking pillows.
- Taking some contact pressure away from the heels.
- Supporting bent knees while resting on the back.
- Creating a stable position for reading or listening.
These are subjective comfort uses. A pleasant position for one person may feel cramped or overly flexed to another.
Who should be cautious?
Anyone with a diagnosed heart, breathing, circulation, spinal or post-surgical condition should ask the relevant clinician about positioning. People using CPAP or another prescribed treatment should not replace it with a bed preset.
How to find your version
- Start flat with your normal pillow.
- Raise the head in small steps until the chest and neck feel supported.
- Add gentle knee elevation.
- Reduce either angle if you feel folded at the hips or pressure behind the knees.
- Save the position only after spending several minutes in it.
Common mistakes
Do not assume the factory preset is anatomically precise, add a tall stack of pillows that forces the neck forward, or sleep all night in a new angle after only a brief test. Ensure the mattress remains in contact with the deck.
Zero gravity versus anti-snore
An anti-snore preset usually applies a modest head lift. Zero gravity also elevates the legs. Neither label guarantees an outcome, and suspected sleep apnoea needs medical assessment.
Questions at a demonstration
Ask whether the preset is customisable, how it works on split sides and how the bed returns to flat during a power interruption. Test the actual mattress because its response changes the posture.
Explore the pros and cons of adjustable beds, learn how presets move the base, or try positions at home in Sydney.
Reviewed by Mattress Point, adjustable bed specialists based in Arndell Park, NSW. General product information; seek individual clinical advice where health or care needs are involved.