When do I need cross braces?

Add cross braces when either canvas dimension exceeds 60 cm. For very large canvases (over 100 cm), use both horizontal and vertical braces forming a cross. Cross braces prevent the stretcher bars from bowing under canvas tension.

How much wrap allowance should I add?

Allow 3-5 cm of fabric beyond the stretcher bar edges for wrapping and stapling. For gallery wrap (where the canvas wraps around the sides), you need extra fabric equal to the bar depth on each side, plus the stapling allowance.

Mortise and tenon vs mitre joints?

Mortise and tenon joints (tongue and groove) are the strongest and allow corner keys for tightening. Mitre joints give a clean corner but are weaker. Stapled butt joints are the simplest but least durable. For professional work, always use mortise and tenon.

What bar depth should I choose?

18 mm bars are fine for small works (under 40 cm). 38 mm is the standard for most canvas sizes. 50 mm (deep edge) gives a gallery-wrap look and more rigidity for larger works. The deeper the bar, the less likely it is to warp.

ArtCalcs

Canvas Stretcher Calculator — Stretcher Bar Cutting

Calculate stretcher bar lengths, canvas fabric and materials for custom canvases.

Canvas Width

Width measurement

Canvas Height

Height measurement

Bar DepthSelect standard or enter custom depth

Corner TypeSelect the type to use

Quantity

Number of items in this batch

How We Calculate This

Stretcher Bar Calculations

Bar lengths: 2 bars at canvas width + 2 bars at canvas height per canvas.

Canvas fabric = canvas size + (wrap allowance × 2) + (bar depth × 2)

Cross braces: Added when any dimension exceeds the threshold (default 60 cm). One brace spans the opposing dimension.

Staples: Approximately one every 5 cm around the perimeter, on both front and back edges.

Frequently Asked Questions

Last updated: March 2026

All calculations are estimates. Always verify quantities before purchasing materials.