Two ways to size a quilt
Start from what you know. If you have chosen a block and want to know where it leads, size the quilt from blocks. If the quilt has to fit a particular bed, size it for the bed and plan blocks and borders to reach that size.
From blocks, sashing and borders
For a straight-set quilt, all in finished sizes:
- Width = blocks across × block size + (blocks across − 1) × sashing + 2 × each border.
- Length = blocks down × block size + (blocks down − 1) × sashing + 2 × each border.
If the sashing also frames the outside of the blocks, add two more sashing widths each way. A 12 ½-inch unfinished block finishes at 12 inches once it is sewn in.
For a bed
The quilt covers the mattress top, hangs over both sides and the foot, and has extra at the head for a pillow tuck:
- Overhang = mattress depth + drop below the mattress.
- Width = mattress width + 2 × overhang.
- Length = mattress length + overhang + pillow tuck.
Measure your mattress depth, topper included. Mattress depth varies a lot between brands.
Mattress and quilt size chart
US mattress tops, with a typical bed quilt for each: a 12-inch mattress, 3 inches of drop below it, and an optional 10-inch pillow tuck.
| Bed | Mattress top | Overhang each side | Quilt, no pillow tuck | Quilt with 10 in pillow tuck |
|---|---|---|---|---|
| Crib | 28 × 52 in | 6 in | 40 × 58 in | – |
| Twin | 38 × 75 in | 15 in | 68 × 90 in | 68 × 100 in |
| Twin XL | 38 × 80 in | 15 in | 68 × 95 in | 68 × 105 in |
| Full | 54 × 75 in | 15 in | 84 × 90 in | 84 × 100 in |
| Queen | 60 × 80 in | 15 in | 90 × 95 in | 90 × 105 in |
| King | 76 × 80 in | 15 in | 106 × 95 in | 106 × 105 in |
| California king | 72 × 84 in | 15 in | 102 × 99 in | 102 × 109 in |
The crib row covers the top and sides of a 6-inch crib mattress with no drop and no tuck. Keep quilts out of the crib while a baby is sleeping there.
A deeper mattress changes everything: at 14 inches deep, the same queen quilt with a tuck grows to 94 × 107 inches.
Example: planning a queen quilt from 12-inch blocks
You want a quilt for a queen bed with a 12-inch mattress, 3 inches of drop and a pillow tuck.
- Target size. 60 + 2 × (12 + 3) = 90 inches wide. 80 + 15 + 10 = 105 inches long.
- Blocks. Six 12-inch blocks across with 2-inch sashing between them make 6 × 12 + 5 × 2 = 82 inches. Seven blocks down make 7 × 12 + 6 × 2 = 96 inches.
- Borders. Two 2-inch borders add 2 × (2 + 2) = 8 inches each way, so the quilt finishes at 90 × 104 inches, an inch short of the target length. That is close enough for a tuck.
- Blocks to make: 6 × 7 = 42.
Borders are the easiest place to adjust. Change their widths to land the length exactly without redesigning the blocks.
Tips
- Measure the bed, not the label. Sheets, toppers and pillow-top mattresses all change the depth. Measure from the top edge of the mattress down to where you want the quilt to stop.
- Plan the borders last. Settle the blocks and sashing first, then use the borders to reach the size you want.
- Cut borders to the measured quilt. Measure your pieced center through the middle both ways and cut borders to that length, not to the planned number. It keeps the edges from waving.
- Allow for take-up. Quilting and the first wash draw a quilt in. How much depends on the batting, the fabric and the quilting density, so add a little if the drop matters.
- Then plan the fabric. Once you know the finished size, the backing and binding calculators give the yardage for the back and the edges.
Frequently asked questions
What size quilt do I need for a queen bed?
A queen mattress is 60 × 80 inches. With a 12-inch-deep mattress, 3 inches of drop below it and 10 inches for a pillow tuck, the quilt should be about 90 × 105 inches. Many queen patterns finish around 90 × 108 inches, which leaves a little more for the tuck.
How do I work out the size of a quilt from its blocks?
Multiply the blocks across by the finished block size, add one sashing strip fewer than the number of blocks, then add each border twice, once for each side. Do the same for the length. Use finished sizes throughout, not the cut sizes with seam allowances.
What is a pillow tuck?
Extra length at the head of the bed that tucks under the front of the pillows and folds back over them. Allowances vary from about 10 to 20 inches depending on the pillows. Leave it out if the quilt will stop at the pillows or be folded at the foot of the bed.
How far should a quilt hang over the side of the bed?
It is a matter of taste. A quilt that just covers the mattress sides is the mattress depth; most bed quilts hang a few inches below that. A bedspread that reaches the floor needs the height from the top of the mattress to the floor. Measure on your own bed with a tape.
Does quilting make a quilt smaller?
Yes. Quilting draws the layers in, and washing shrinks cotton batting and unwashed fabric. Dense quilting draws in more than sparse quilting. Make the top a couple of inches larger each way if the drop must be exact, or quilt and wash a sample to measure.
What size is a crib quilt?
Crib quilts are commonly around 36 × 52 inches. Safe-sleep guidance from the American Academy of Pediatrics says to keep quilts and other soft bedding out of a baby's sleep space, so crib-size quilts are usually used for play, tummy time or the wall until the child is older.
Last updated October 17, 2026.