Plan fabric for rectangular pieces
Use this fabric calculator when you have a list of rectangular pieces and need to estimate the length of a fixed-width roll. It is useful for simple panels, patchwork rectangles, bag components and craft projects. Add one row for each size and set the quantity, rather than entering every identical piece separately. All pieces in one calculation share the same fabric and allowance. Calculate different fabrics separately.
The result includes a cutting layout, the length that layout occupies, and a separate length with your chosen extra percentage. It is a practical arrangement you can inspect, not a promise of the shortest possible layout. Check the actual fabric and your pattern instructions before buying or cutting.
How to enter your measurements
First choose centimeters or inches and measure the usable width across the fabric, excluding selvages or damaged edges you will not cut. The width field describes one flat layer, not folded fabric. Changing units converts existing measurements and rounds them to four decimal places, so check converted values if a piece fits the width exactly.
Enter finished width, finished length and a whole quantity for every piece type. Width is across the roll and length follows the roll. Allowance per edge is added twice to each dimension: cut width = finished width + 2 × allowance, and cut length = finished length + 2 × allowance. If your measurements already include seams or hems, set allowance to zero. Different edge allowances must be included manually in each cut dimension with the shared allowance at zero.
Allow 90° rotation only for pieces that may turn across the grain. Leave it off for directional fabric or a required grain direction. Choose your own extra percentage, then press Calculate layout. Adding or editing a piece clears the previous result until you calculate again, so an old plan cannot be mistaken for the new measurements.
How the layout determines fabric length
The calculator expands all quantities into individual rectangles. It tries three fixed ordering rules and places the pieces in horizontal rows, reusing room in an existing row when possible. Permitted rotations are considered while placing each piece. It keeps the shortest of these three valid plans. Every piece stays within the usable width and has its own non-overlapping space. A different nesting method or a manual arrangement may use less fabric.
Length comes from the bottom edge of the completed layout, not total piece area divided by fabric width. Free space shows unused area inside that layout, excluding your additional length. The extra percentage is applied to the layout length: extra-inclusive length = layout length × (1 + percentage / 100). It does not change piece dimensions or model shrinkage. The extra-inclusive lengths are rounded upward to two decimal places; retailer selling increments are not applied.
Example 1: two sizes on 140 cm fabric
Use the starting values: four 40 × 40 cm finished pieces and two 20 × 30 cm pieces, 1 cm allowance per edge, no rotation, and 140 cm usable width. Cut sizes become 42 × 42 and 22 × 32 cm. Three squares fit in the first row. The remaining square and both smaller rectangles fit in the second row. The layout length is 84 cm. With 10% extra it becomes 92.4 cm, displayed also as 0.93 m after upward rounding. The percentage is an example you may change, not a recommended allowance.
Example 2: four panels in inches
For four 20 × 12 in cut panels, use 45 in fabric width, zero edge allowance, zero extra and rotation off. Two panels fit across each row, and two rows use 24 in of fabric. The extra-inclusive result remains 24 in, also displayed as 0.67 yd rounded upward. Dividing panel area by width would give about 21.33 in, which is not enough for this displayed arrangement.
Check the plan and keep the result
Each rectangle has a type-and-copy number such as 1.2. Open the exact dimensions and positions below the drawing to match it to the cut list. Positions start at the upper-left corner: the first coordinate runs across the width, the second along the length. A turn symbol identifies a rotated piece. Very small pieces may omit their number in the drawing; every piece remains in the list.
Copy result includes the lengths, cutting dimensions and coordinates from this same plan. Paste it into your notes; if clipboard access fails, select the provided summary manually. The drawing is scaled to fit the screen and is not a full-size template. The calculator does not save a project after leaving the page.
Fabric calculator FAQ
Why does a piece fail to fit?
The cutting width includes allowance on both edges. Reduce the intended cut width only if your pattern permits it, use wider fabric, or allow rotation when appropriate. Pieces are never split or joined automatically.
Can I enter fractions or many pieces?
Use decimals such as 0.5 instead of 1/2. A dot or comma is accepted as a decimal separator, with up to four decimal places and no thousands separators. Enter 1–20 types, at most 200 pieces total, positive dimensions up to 10,000 in the selected unit, and extra from 0 to 100%.
Does this account for pattern matching or shrinkage?
No. Repeating motifs, nap alignment, shrinkage and fabric defects need separate planning. Disabling rotation only preserves the entered axes; it does not align motifs or evaluate the textile.
Can I use it for curved clothing patterns?
Only rectangular cutting envelopes are supported. Curves, mirrored pairs, pieces cut on a fold, bias cuts and interlocking shapes are not modeled. Follow the pattern’s layout when those details matter.
Is the result the minimum I should buy?
No. It is the length for the shown feasible arrangement plus your optional extra. Compare your cut list with the real fabric, confirm allowances, and round up to the seller’s available increment yourself.