Loft vs firmness: the two numbers that decide how a pillow feels

Pillow descriptions throw around "loft", "firmness", "support" and "plush" as if they all meant the same thing. They do not. Loft is about height; firmness is about how much the pillow resists being squashed. You need both numbers to predict where your head will actually end up at 3am — and that final resting height is what your neck cares about.

What loft means

Loft is the height of a pillow sitting on a flat surface with nothing on it. Retailers usually group it into low, medium and high. Exact cut-offs vary between brands, but a rough guide is:

• Low loft: under about 7–8 cm (around 3 inches).
• Medium loft: roughly 8–13 cm (around 3 to 5 inches).
• High loft: above about 13 cm (5 inches or more).

Measure your own pillow by laying it on a table, placing a ruler upright beside the middle, and resting a flat book lightly on top so you read the height at the peak rather than the fluffiest wisp of fill.

What firmness means

Firmness is how strongly a pillow pushes back. A soft pillow lets your head sink in a long way; a firm one barely gives. Brands describe it with words, not a standard scale, so "medium" from one maker may feel like "firm" from another.

A home test: press your palm into the middle of the pillow with about the pressure of a resting head (lighter than you might think — an adult head weighs roughly as much as a bowling ball, but spread over a wide area). Notice how far your hand sinks and how quickly the pillow pushes back. A soft pillow swallows most of your hand; a firm one leaves you barely below the surface.

Why the two combine

What matters in bed is the compressed height: how high your head sits once it has sunk in. That depends on both numbers together.

Loft and firmness combined: where your head ends up

	Soft	Medium	Firm
Low loft	Very low — stomach sleepers	Low — stomach or small-framed back sleepers	Low but unyielding — can feel hard
Medium loft	Low-medium — stomach or back	Medium — many back and combination sleepers	Medium-high — back or narrow-shouldered side sleepers
High loft	Medium — plush feel, can suit back sleepers who like to sink	High — side sleepers	Very high — broad-shouldered side sleepers

This is why a "high loft" down pillow can end up sitting lower under your head than a "medium loft" latex one. It is also why reading only one of the two numbers leads so many people to buy the wrong thing.

Other things that change the compressed height

• Your mattress. On a soft mattress your shoulders and body sink, so you need less pillow height. On a firm one you need more.
• Your head and body size. A heavier head compresses a pillow more. Broader shoulders create a bigger gap for side sleepers to fill.
• Time. Down and fibre flatten over the night and need fluffing in the morning. Memory foam softens as it warms. A pillow can feel different at midnight than at 6am.
• Age. All pillows lose loft as they wear. An old pillow of the right model may still be the wrong height.
• Pillow protectors and cases. A thick quilted protector adds a little height and firmness; a tight case can compress a pillow noticeably.

A simple way to find your target

1. Decide your main sleep position (see the combination sleeper guide if you are not sure).
2. For side sleeping, measure from the outside of your shoulder to the side of your head; that is the compressed height to aim for.
3. For back sleeping, aim for a height where your face points at the ceiling.
4. For stomach sleeping, aim for as low as you find comfortable.
5. Test your current pillow and note whether it is too high, too low or right. That tells you which way to move on loft and firmness when you shop.

Our homepage has a quick pillow matcher that walks through these same questions and suggests a starting range. It is a rough guide, not a prescription: comfort is personal.

Frequently asked questions

Is a firmer pillow more supportive?

Not necessarily. Support means keeping your head in line with your spine. A firm pillow that is too tall is unsupportive in that sense, and a soft pillow of the right compressed height can be very supportive.

Why do product listings give different heights for the same pillow?

Some brands measure a freshly fluffed pillow, others measure after compression or after shipping. Treat listed heights as approximate and check the return or exchange terms before buying.

Can I change a pillow's loft?

Adjustable pillows let you remove fill. With down or fibre, a pillow protector or thin second pillow can raise height slightly. Solid foam cannot be adjusted.