How Do I Measure Artwork for a Custom Frame?

The most important measurement for a custom frame is the exact size of your artwork—not the size of an existing frame or the visible image. Measure the full width and height of the artwork to the nearest 1/16 inch (or nearest millimetre), then order a frame designed for those dimensions. If you plan to use a mat, the outside frame size will be larger, but the frame itself is still selected based on the artwork dimensions.

At Custom Frames Canada, one of the most common causes of ordering mistakes is measuring the wrong part of the artwork. This guide explains exactly what to measure for every major type of artwork.

Quick Answer

Measure only the artwork itself:

• Width: Left edge to right edge
• Height: Top edge to bottom edge
• Do not measure the existing frame
• Do not measure the visible opening
• Do not guess the size
• Measure twice before ordering

If your artwork is already framed, remove it from the frame if possible before measuring.

What You'll Need

• Steel measuring tape or metal ruler
• Flat work surface
• Pencil and paper (or your phone)
• Good lighting

For large artwork, having a second person help can improve accuracy.

Step 1: Lay the Artwork Flat

Place the artwork on a clean, flat surface.

Avoid measuring while it is hanging on a wall or leaning against furniture, as this often introduces small errors.

Step 2: Measure the Width

Measure from the outside edge on the left to the outside edge on the right.

Do not round measurements up or down.

Example:

Correct:

24 3/16"

Not:

24"

Step 3: Measure the Height

Measure from the very top edge to the very bottom edge.

Again, record the exact measurement.

Example:

36 1/8"

Step 4: Record Your Measurements

Write them as:

Width × Height

Example:

24 3/16 × 36 1/8 inches

This becomes the basis for your custom frame.

Measuring Different Types of Artwork

Paper Prints

Measure the entire sheet, including any white borders.

Do not measure only the printed image.

Photographs

Measure the full photograph from edge to edge.

Even if part of the photo will be covered by a mat, the frame is built around the complete photograph.

Posters

Movie posters often vary slightly from their advertised size.

Never assume a poster labelled "24 × 36" is exactly 24 × 36 inches.

Always measure the actual poster.

Canvas Paintings

Measure the front dimensions of the stretched canvas.

For a floater frame, also measure the canvas depth (thickness).

Typical depths include:

• 3/4 inch
• 1 inch
• 1.5 inches

The depth determines which floater frame profile is appropriate.

Diplomas

Measure the paper itself—not the existing frame or mat.

Many universities use similar diploma sizes, but slight differences are common.

Always verify your individual diploma before ordering.

Certificates

Certificates should be measured exactly like diplomas.

Artwork Already in a Frame

If possible:

1. Remove the artwork.
2. Measure the artwork itself.

If the artwork cannot be removed safely, measure the visible opening and contact us before ordering.

Common Measuring Mistakes

The most frequent mistakes we see include:

❌ Measuring the outside of an existing frame

❌ Measuring only the visible image

❌ Assuming the listed artwork size is accurate

❌ Rounding dimensions

❌ Forgetting canvas depth

❌ Confusing centimetres and inches

Taking a few extra minutes to measure carefully can prevent ordering the wrong size.

Do I Measure the Frame or the Artwork?

Always measure the artwork.

A custom frame is built around the artwork dimensions.

The outside dimensions of the finished frame will depend on:

• moulding width
• mat size
• frame profile

What If I'm Using a Mat?

The artwork size stays the same.

Only the finished outside dimensions become larger.

Example:

Artwork:

16 × 20

Mat border:

2 inches

Approximate finished frame:

20 × 24

Our Frame Size Calculator can calculate the exact finished dimensions.

Measuring in Inches or Millimetres

Either measurement system works.

For North American framing, inches are the most common.

For technical drawings and many international artworks, millimetres may provide greater precision.

Be consistent throughout the ordering process.

Special Considerations for Oversized Artwork

Large artwork can flex while being measured.

For pieces over approximately 40 inches:

• Lay the artwork completely flat.
• Use a rigid measuring tape.
• Measure twice.
• Have another person verify the measurements if possible.

Before You Order

Double-check:

✓ Width

✓ Height

✓ Canvas depth (if applicable)

✓ Units (inches or millimetres)

✓ Mat requirements

✓ Orientation

Frequently Asked Questions

Should I measure the artwork or the frame?

Always measure the artwork.

Should I include the white border around a print?

Yes. Measure the entire sheet.

Should I measure the visible image?

No.

Measure the complete artwork.

What if my artwork is 24 1/8 inches?

Order a custom frame built for 24 1/8 inches.

Do not round to 24 inches.

Do custom frames allow for manufacturing tolerances?

Professional custom frames are manufactured with a small internal allowance so the artwork fits properly, but customers should always provide the exact artwork dimensions rather than attempting to add extra clearance themselves.

How do I measure a canvas for a floater frame?

Measure:

• Width
• Height
• Canvas depth

All three measurements are required.

Need Help Measuring?

If you're unsure about your measurements, we're happy to help.

Simply contact Custom Frames Canada before ordering. Our team can help you verify measurements for photographs, posters, diplomas, canvases, oversized artwork, and other custom framing projects.

You can also use our Frame Size Calculator to determine the correct frame dimensions after measuring your artwork.

Related Guides

• Frame Size Calculator
• Standard Picture Frame Sizes
• Acrylic vs. Glass
• Canvas Floater Frame Guide
• Standard Diploma Sizes
• How Much Does Custom Framing Cost?