🎨 Canvas Stretcher Calculator

Calculate Fabric Size & Frame Requirements

Extra fabric for stapling (back)

🎨 Canvas Stretching Guide

Stretching your own canvas gives you control over the size, depth, and fabric quality. The key is calculating the correct amount of extra fabric needed to wrap around the bars and staple to the back.

The Formula

Total Width = Frame Width + (2 × Depth) + (2 × Wrap Allowance)

Example: For a 24" wide frame with 1.5" depth and 2" wrap allowance:
24 + (2 × 1.5) + (2 × 2) = 24 + 3 + 4 = 31 inches

Cross Bracing Rules

  • Under 30": No bracing usually needed.
  • 30" - 48": Single cross brace recommended to prevent bowing.
  • Over 48": Double bracing or a cross (+) design is essential.
  • Heavy Duty Bars: Thicker bars (1.5"+) can span longer distances without bracing than thin (3/4") bars.

Wrap Allowance Guide

  • Standard Wrap (Staples on side): Depth + 1 inch
  • Gallery Wrap (Staples on back): Depth + 1.5 to 2 inches
  • Splined Canvas: Depth + 0.5 to 1 inch (fits into groove)
💡 From Elena Rossi, Fine Art Restorer (20 years):

"Always cut your canvas slightly larger than you think you need. You can always trim excess fabric after stapling, but you can't add it back if you come up short! Also, if you're working with raw cotton or linen, remember to account for shrinkage (approx 5-8%) if you plan to size/prime it yourself after stretching."

⚠️ Common Mistakes

1. Forgetting the Depth: Beginners often add the wrap allowance but forget to add the thickness of the bar itself. This leaves the raw canvas edge visible on the side.

2. Skipping Braces: A 36x48" canvas on 3/4" bars WILL warp and twist over time without a cross brace. Don't risk your artwork!

3. Uneven Tension: Pulling too tight on the first side makes it impossible to stretch the opposite side. Work from the center outwards, rotating sides frequently.

Reviewed by Elena Rossi
Professional Fine Art Restorer & Framer, 20 years experience in canvas preparation and conservation.