Bed friction data: how much resistance does your bed create?
Every bed surface creates friction that you must overcome to turn, reposition, or adjust at night. Below is measured coefficient of friction (CoF) data for common bed surface combinations — from cotton sheets to mattress protectors to slide sheets. These numbers show exactly why some bed setups make turning easy and others make it feel like you're stuck in place.
This content focuses on comfort, everyday movement, and sleep quality at home. It is not medical advice, does not diagnose or treat conditions, and Snoozle is not a medical device. Friction values are approximate and based on standardised fabric-on-fabric pull testing. Individual results vary with body weight, moisture, and surface condition.
What is the friction coefficient of different bed surfaces?
Coefficient of friction (CoF) measures the ratio of sliding force to pressing force. Lower numbers mean less resistance. For an 80kg person, each 0.1 reduction in CoF removes roughly 8kg of lateral push force needed to start a turn.
| Surface combination | CoF (static) | Force to turn (80kg person) | Category |
|---|---|---|---|
| Cotton on waterproof protector | 0.55 – 0.65 | ~44 – 52 kg | Very high |
| Flannel on flannel | 0.50 – 0.60 | ~40 – 48 kg | Very high |
| Cotton pyjamas on cotton sheet | 0.40 – 0.50 | ~32 – 40 kg | High |
| Cotton on memory foam (no sheet) | 0.45 – 0.55 | ~36 – 44 kg | High |
| Microfibre sheet on spring mattress | 0.30 – 0.35 | ~24 – 28 kg | Moderate |
| Satin/silk sheet | 0.20 – 0.25 | ~16 – 20 kg | Low (uncontrolled) |
| Snoozle Slide Sheet | 0.10 – 0.15 | ~8 – 12 kg | Very low (controlled) |
CoF values measured via standardised fabric-on-fabric pull testing. "Force to turn" is a simplified calculation: body weight × CoF × contact area factor. Actual turning involves rotational mechanics and partial body weight, so real forces are lower — but the proportional differences between surfaces hold.
How much force does it take to turn over in bed?
The force needed to initiate a turn depends on your weight, the friction of your bed surfaces, and how much of your body is in contact with the mattress. For an 80kg person lying on their side with roughly 40% body contact:
- —Cotton on protector (CoF 0.60): ~19kg lateral force to break static friction. That's like pushing a heavy suitcase sideways.
- —Cotton on cotton (CoF 0.45): ~14kg. Still requires a deliberate push that engages core and shoulders.
- —Snoozle Slide Sheet (CoF 0.12): ~4kg. A gentle hip shift — the kind you can do without fully waking.
The 70% reduction in turning force is the difference between a movement that wakes you up and one that happens in your sleep.
Does memory foam increase bed friction?
Yes — memory foam increases bed friction in two distinct ways. First, the foam surface itself has a higher coefficient of friction than spring mattress tops. Second, the foam conforms to your body shape and creates a depression that adds a mechanical barrier to lateral movement. You're not just fighting surface friction — you're climbing out of a valley.
Combined, memory foam can increase the functional effort to turn by 40–60% compared to a spring mattress with identical sheets. A slide sheet addresses the surface friction component directly, making the conformity effect more manageable.
Do mattress protectors increase bed friction?
Significantly. Waterproof mattress protectors with a polyurethane or rubber backing are often the single biggest source of bed friction — more than the mattress itself or the sheets. They measure a CoF of 0.50–0.65 against cotton sheets, compared to 0.40–0.50 for cotton on a bare mattress surface.
If you use a protector and find turning difficult, the protector may be contributing more resistance than you realise. A slide sheet placed above the protector eliminates this friction layer from your contact surface.
How we measure bed friction
All CoF values on this page are measured using a standardised fabric-on-fabric pull test: a weighted sled (simulating body contact pressure) is placed on the test surface and pulled laterally with a force gauge. Static CoF is the force needed to initiate movement; kinetic CoF is the force to maintain it.
We report static CoF because that's what you fight when starting a turn. Once moving, kinetic friction is lower — but the initial "break free" force is what wakes you up and causes pain.
Where Snoozle fits in the data
The Snoozle Slide Sheet measures a static CoF of approximately 0.10–0.15, making it the lowest-friction consumer bed surface we have tested. Unlike satin sheets (CoF 0.20–0.25), the Snoozle uses directional, controlled friction — low when you initiate movement, stable when you're still. This means you get the turning benefit without sliding off the bed unintentionally. For the full product details, see What is Snoozle?
Frequently asked questions about bed friction
What is the friction coefficient of bed sheets?▼
Standard cotton percale sheets have a CoF of ~0.40–0.50 against cotton sleepwear. Flannel measures 0.50–0.60. Satin measures 0.20–0.25. Microfibre is ~0.30–0.35. Slide sheets like Snoozle measure 0.10–0.15.
How much force does it take to turn over in bed?▼
For an 80kg person on cotton sheets: roughly 14kg of lateral force. On a Snoozle Slide Sheet: roughly 4kg. The 70% reduction is the difference between waking up to turn and turning in your sleep.
What bed surface has the lowest friction?▼
Purpose-built slide sheets. The Snoozle measures ~0.10–0.15. Satin sheets are next at 0.20–0.25 but lack directional control — you can slide unintentionally when still.
Does memory foam increase bed friction?▼
Yes. Memory foam increases friction through higher surface grip plus body conformity (creating a depression you must climb out of). Combined, it increases turning effort by 40–60% vs. a spring mattress with the same sheets.
Do mattress protectors increase friction?▼
Significantly. Waterproof protectors with rubber/polyurethane backing measure CoF 0.50–0.65 — often the highest-friction layer in the bed. A slide sheet above the protector eliminates this friction source.