Comforter Size Calculator

The short answer

A comforter needs to be as wide as the mattress plus the drop you want on both sides, and as long as the mattress plus that drop at the foot. To just cover the sides, the drop is the mattress depth. For a fuller look, let it hang a little past that. On a queen mattress 12 in deep, a 16 in drop calls for about 92 × 96 in, which a Full/Queen comforter (92 × 92 in) covers. A standard queen comforter, 88 × 92 in, hangs 14 in at each side.

How to measure

1. Check the bed size: twin, twin XL, full, queen, king or California king.
2. Measure the mattress depth from its top to its bottom edge, including a pillow top or a topper you use every day.
3. Decide on the look: just covering the mattress sides, hanging a little past them, or long, almost to the floor.
4. On the label, look for the comforter’s width and length, not only its size name: sizes with the same name differ by a few inches between brands.

How to use the calculator

1. Pick your bed and enter the mattress depth.
2. Choose how far down you’d like the comforter to hang.
3. Read the result: the size to buy, how far it hangs at the sides and the foot, and how the other sizes for your bed compare.
4. Save or share it. Copy link keeps your numbers in the address.

How we calculate

Comforter sizes differ by a few inches between brands, so treat the sizes below as typical and check the label.

• Drop: the mattress depth to just cover the sides; 4 in more to hang a little past them; and at least 20 to 22 in for a floor-length drop.
• Size needed: the mattress width plus the drop twice, and the mattress length plus the drop once, so the comforter hangs about as far at the foot as at the sides.
• Standard sizes: twin 68 × 88 in, twin XL 68 × 90 in, full 82 × 86 in, queen 88 × 92 in, king 106 × 92 in and California king 108 × 96 in. Comforters also come in a full/queen size, about 92 × 92 in, and an oversized queen, about 98 × 98 in.
• Fit: a size Fits when it hangs as far as you want at the sides, and is Tight when it covers the mattress sides but hangs less, or doesn’t cover the foot. For each bed we try its own size, then a full/queen or oversized size, then the next bed size up, and recommend the first one that fits.
• The drawing puts the mattress on a bed about 25 in high, a standard bed height, to show where the drop ends.

Worked examples

Worked example

A queen bed with a 12 in mattress

What we know

• Bed: queen, 60 × 80 in
• Mattress depth: 12 in
• Look: a little past the mattress

How it works out

1. Drop: 12 in + 4 in to hang a little past the mattress = 16 in.
2. Width: 60 in + 2 × 16 in = 92 in. Length: 80 in + 16 in = 96 in.
3. Full/Queen, 92 × 92 in: (92 in − 60 in) ÷ 2 = 16 in at the sides.

On a queen mattress 12 in deep, a comforter that hangs 16 in at the sides (a little past the mattress) needs to be about 92 × 96 in. A Full/Queen (92 × 92 in) hangs 16 in at the sides and 12 in at the foot.

Worked example

A queen bed with a 15 in pillow-top mattress

What we know

• Bed: queen, 60 × 80 in
• Mattress depth: 15 in
• Look: a little past the mattress

How it works out

1. Drop: 15 in + 4 in to hang a little past the mattress = 19 in.
2. Width: 60 in + 2 × 19 in = 98 in. Length: 80 in + 19 in = 99 in.
3. Oversized queen, 98 × 98 in: (98 in − 60 in) ÷ 2 = 19 in at the sides.

On a queen mattress 15 in deep, a comforter that hangs 19 in at the sides (a little past the mattress) needs to be about 98 × 99 in. An Oversized queen (98 × 98 in) hangs 19 in at the sides and 18 in at the foot.

Worked example

A twin XL dorm bed with an 8 in mattress

What we know

• Bed: twin xl, 38 × 80 in
• Mattress depth: 8 in
• Look: just covering the sides

How it works out

1. Drop: the mattress depth, 8 in, to cover the sides.
2. Width: 38 in + 2 × 8 in = 54 in. Length: 80 in + 8 in = 88 in.
3. Twin XL, 68 × 90 in: (68 in − 38 in) ÷ 2 = 15 in at the sides.

On a twin xl mattress 8 in deep, a comforter that hangs 8 in at the sides (just covering the sides) needs to be about 54 × 88 in. A Twin XL (68 × 90 in) hangs 15 in at the sides and 10 in at the foot.

Comforter size chart

The typical comforter for each bed and how far it hangs down the sides of the mattress.

Comforter width by mattress depth

The width a queen bed needs as the mattress gets deeper. A standard mattress is 10 to 12 in deep, a thick one 12 to 14 in and an extra-thick one 14 in or more.

Before you buy

Still choosing the bed? The bed size calculator shows which mattress fits your room with space to walk around it.

Duvet covers come in about the same sizes as comforters. When you buy an insert and a cover separately, the insert is usually the same size as the cover or a few inches larger, so compare the two labels rather than the size names.

Sizing up adds more drop at the sides than at the foot: a king comforter on a queen bed hangs 23 in at each side but only 12 in at the foot. On a queen bed, an oversized queen comforter (98 × 98 in) hangs about as far at the foot as at the sides.