Written and maintained by CASRAI Editorial Board
Last updated
This page describes products and general use; it is not medical advice.
Adjustable bed dimensions follow the standard mattress sizes: a base is made to match the width and length of the mattress it carries. Casper’s published chart lists Twin at 38 x 75 inches, Queen at 60 x 80 inches and King at 76 x 80 inches, and notes the footprint may shift slightly with the frame style. This guide is for readers and facility staff who need to check that a base fits the room and the mattress, and who need to tell a home adjustable base from a regulated hospital bed.
What an adjustable bed base is
An adjustable bed base is a bed frame whose sleeping surface can be raised and lowered in sections, usually the head and foot, and is paired with a mattress designed to flex. Casper advises pairing a base with a mattress “designed to flex smoothly”. Home bases are consumer furniture. Hospital beds are a separate, regulated category (see below).
Who uses it: households choosing a base for a standard mattress, and facility staff comparing a home-style base with a hospital bed.
Adjustable bed sizes (width x length)
Adjustable bases use the same size names as conventional mattresses. These are the nominal sizes published by one manufacturer, Casper (checked 2026-10-30).
| Size | Width (in) | Length (in) | Source |
|---|---|---|---|
| Twin | 38 | 75 | Casper |
| Twin XL | 38 | 80 | Casper |
| Full | 54 | 75 | Casper |
| Queen | 60 | 80 | Casper |
| King | 76 | 80 | Casper |
| California King | 72 | 84 | Casper |
The same source states that “the footprint may shift slightly based on design or frame style,” so the product’s own specification sheet governs the exact outer dimensions of any base.
Split sizes
A split king or split queen uses two bases side by side so each sleeper can adjust their own side. According to Casper, a split king surface remains exactly 76 x 80 inches and a split queen footprint stays 60 x 80 inches, the same as the unsplit size.
Home adjustable base versus an FDA-regulated hospital bed
In US federal regulation, an AC-powered adjustable hospital bed is defined in 21 CFR 880.5100 as “a device intended for medical purposes that consists of a bed with a built-in electric motor and remote controls that can be operated by the patient to adjust the height and surface contour of the bed,” and the device “includes movable and latchable side rails.” It is a Class II device under special controls (eCFR, checked 2026-10-30). A bed sold as household furniture is not described by this definition, so the size chart above should not be read as hospital bed dimensions.
For hospital beds, FDA publishes the guidance Hospital Bed System Dimensional and Assessment Guidance to Reduce Entrapment (March 2006), which recommends dimensional criteria to reduce entrapment. For classes, codes and the entrapment zones, see hi-lo beds, bed rail covers and what a hospital bed is. For lifting and transfers see patient lifts.
How to check fit
- Match the base size name to the mattress size name, and confirm both against the product specification sheet.
- Measure the delivery route, including door frames and tight corners; Casper notes many bases ship in sections.
- Allow for room: Casper suggests roughly a 10 x 10 ft room for a queen and about 12 x 12 ft for a king or California king (the company’s suggestion, not a standard).
- Adjustable legs, where offered, let the owner tailor bed height (Casper).
Common mistakes
- Treating a nominal chart size as the exact outer dimension of the frame.
- Assuming a split king is wider than a king; the stated surface is the same 76 x 80 inches.
- Assuming a household base meets the definition of a hospital bed in 21 CFR 880.5100.
FAQ
What are the standard adjustable bed sizes?
Twin, Twin XL, Full, Queen, King and California King, matching mattress sizes. In Casper’s chart they run from 38 x 75 inches (Twin) to 76 x 80 inches (King) and 72 x 84 inches (California King).
Is an adjustable bed the same size as a regular bed?
The size names are the same, but the base footprint can differ slightly by design or frame style, so check the specification sheet.
Is a hospital bed the same as an adjustable bed?
No. 21 CFR 880.5100 defines an AC-powered adjustable hospital bed as a medical device with built-in motor, remote controls and latchable side rails, regulated by FDA as Class II.
Sources
- Casper, Adjustable Bed Sizes + Dimensions Guide, checked 2026-10-30.
- eCFR, 21 CFR 880.5100, AC-powered adjustable hospital bed, checked 2026-10-30.
- FDA, Hospital Bed System Dimensional and Assessment Guidance to Reduce Entrapment, checked 2026-10-30.
