MetraNest
EN

Fabric & sewing

Cushion fabric calculator

Plan fabric for flat zipped or envelope cushion covers. The calculation converts finished dimensions into cutting pieces, then arranges them in rows across the fabric width.

Your project measurements

Metric units
cm
cm
cm
cm
cm
cm
%
Your own allowance for cutting waste and reserve. It does not replace an installation plan.

Need a starting point? The initial values are an example.

YOUR ESTIMATE

1.35 m

Fabric length including allowance

Illustrative diagram. Fronts and any back sections arranged in rows; cutting rectangles shown in proportion. Result: 1.35 m140 cm129 cm8 pieces · rows without rotation · excludes extra allowanceIllustrative diagram1.35 m
Width of each piece to cut43 cm
Height of a full fabric piece43 cm
Pieces per row3 pieces
Total pieces8 pieces
Purchase rounded up to 10 cm1.4 m

Separate rows for each piece size, without rotation or offcut optimisation. The calculation is for flat covers without a gusset.

Fabric shrinkage and pattern matching are not modelled. Use the prepared fabric width and add a reserve suited to your fabric.

Understand the calculation
  1. Each full fabric piece measures 43 × 43 cm, including seam allowances.
  2. 140 ÷ 43 allows 3 pieces per row.
  3. 8 fabric pieces arranged in 3 rows of 43 cm.
  4. Total length 1.29 m; with a 5% allowance: 1.355 m.

The estimate depends on your measurements and entered inputs. PDF output uses your browser’s Save as PDF option.

MetraNest · https://metranest.com/en/calculators/cushions/ · Méthode : Face entière = dimensions finies + 2 × marge de couture. Pièces par rangée = partie entière de laize ÷ largeur de coupe. Les rangées sont arrondies par taille de pièce, puis leur longueur totale reçoit la marge choisie.

Start with your intended cover

Start by choosing the finished cover dimensions. They do not necessarily match the cushion insert: the result depends on the design and fabric. The calculation uses your chosen dimensions and does not impose an ease allowance.

Add seam allowances

An allowance on each edge is added twice to a piece’s width and height. The zipped version has two full pieces. The envelope version has one front and two back sections, with their overlap and hem. Frills, gussets and decorative strips are not included.

Read the fabric layout length

The number of pieces fitting across the fabric determines the rows. For envelope covers, fronts and back sections are counted in separate rows. The tool does not rotate pieces or optimise offcuts between different sizes. An allowance is added afterwards; allow separately for shrinkage and pattern matching.

The formula
Full fabric piece = finished dimensions + 2 × seam allowance. Pieces per row = whole number of cutting widths that fit across the fabric. Rows are rounded up for each piece size, then the chosen allowance is added to their total length.

Two square zipped covers

Two finished 40 × 40 cm covers with a 1 cm seam allowance on each edge require four 42 × 42 cm pieces. Three pieces fit across fabric that is 140 cm wide. Two rows use 84 cm of fabric when the extra allowance is set to zero. The purchase length rounded up to 10 cm is 90 cm.

Details to check

  • Use the fabric width actually available after excluding any unusable selvedges.
  • Draw the fabric pieces and their orientation before cutting.
  • Calculate strips or decorative elements separately.

Frequently asked questions

Does a zip require extra fabric?

That depends on the construction. The seam allowance must match your pattern or chosen method.

How is the envelope back calculated?

Two back sections overlap. Each section’s height includes half the finished height, half the overlap, one seam allowance and the hem allowance entered.

Method and references · Editorial review: 25 October 2026

    The geometric formulas are explained here. For a product, its packaging dimensions and coverage rate remain the reference inputs.

    Find the right tool

    Your privacy

    Your dimensions and projects stay on this device. Sharing links contain calculation inputs in the part of the address after #.

    Essential functions

    A project is saved only when you ask.

    Always available

    No analytics service is active.

    No advertisements or affiliate trackers are loaded in this version.

    Learn more and delete my local data

    Add to a project

    A project with the same name groups your calculations. The save remains in this browser. Export a JSON copy to keep it elsewhere.

    Share this calculation

    This link contains the displayed inputs, without your project name. Copy it to reopen the same calculation.