Sleep Number i8 Smart Bed

Under the Smart 3D knit cover sit comfort foams, a temperature-balancing layer, and then the two air chambers that are the actual mattress. A pump in a bedside unit inflates each side independently between Sleep Number settings of 0 to 100.

The sleep number is air pressure, not firmness in the conventional sense. That distinction matters: raising the number firms the surface by increasing chamber pressure, but the comfort layer above it is unchanged, so the range of feel is narrower than the 0–100 scale implies.

SleepIQ sensors in the bed estimate heart rate, breathing rate and movement per side and feed the app. Responsive Air adjusts pressure through the night as you change position.

Cooling: a 3.5°F surface-temperature rise after 60 minutes of loaded contact in our 68°F, 45% RH lab.

Edge support: 2.3 inches of compression under a 230 lb seated load at the perimeter.

Motion transfer: 0.07g peak with a 10 lb weight dropped 12" away.

Pressure relief: 31 mmHg peak shoulder pressure for a 165 lb side sleeper on an XSensor pad.

Response time: 0.6 seconds to fully rebound after release of a 25 lb compression.

Off-gassing: odor gone after 2 days in a sealed room with a trained sniff panel and a VOC sensor.

Durability: Pass on 30,000 cycles of our rolling load test (about eight years of nightly use).

Measured January 2026 under methodology v2.1.

Weeks 1–3: expect to change your number several times a night for the first fortnight. Our testers converged on their final settings around day 12, and Sleep Number's own guidance to give it 30 nights is sound.

Months 2–4: no pressure loss, no pump faults. A firmware update arrived and installed without incident, which is worth noting because a bed that needs firmware is a bed that can fail in software.

Month 6: the comfort layer showed 0.5 inches of impression at the hips — more than the hybrids in this article, because there is less material to distribute the load. The chambers themselves are the durable part; the foams above them are the wear item, and they are replaceable, which is a real advantage over a sealed mattress.

Skip the i8 if you and your partner agree on firmness. At $3,099 you can buy a substantially better-feeling conventional mattress and keep $1,300, and you avoid a pump, hoses and firmware in your bedroom.

Skip it if you sit on the edge of the bed to dress — the edge collapse is real. Skip it if temperature rather than firmness is your disagreement; an Eight Sleep Pod or a cooling hybrid handles that far better.

Read the return terms before ordering. The 100-night trial carries a return shipping fee, and bases and accessories are generally non-returnable, which makes a bundled purchase harder to unwind than a boxed mattress.