Measuring a picture frame correctly is essential when you're framing a photograph, artwork or even a cherished keepsake. A frame that doesn’t fit well can look awkward, fail to protect the piece or even damage it over time. Whether you’re custom framing or buying a ready-made frame online, understanding how to measure accurately helps you make the right purchase and achieve a professional finish.
In this guide, we’ll walk you through the steps of measuring a picture frame, explain the terminology (like frame size vs. image size vs. mat size) and offer tips to ensure your framed piece looks perfect every time.
Choosing the correct frame size ensures that your artwork or photo fits securely, lies flat, and looks professionally displayed. If the frame is too small, the image won’t fit without trimming. If it’s too big, the image might shift around, making it look unpolished.
Proper measurement also helps you choose appropriate matting and ensures that your piece aligns with your wall decor plan, especially when coordinating multiple frames in a gallery wall or matching sizes for a balanced aesthetic.
Before you grab your tape measure, it's important to understand a few basic framing terms:
1. Image Size
This refers to the actual size of the artwork or photo you want to frame. It’s the visible part of the piece that you want to showcase.
2. Mat Opening Size
If you're using a mat (a border that surrounds the image inside the frame), this is the window cut into the mat board. It is typically slightly smaller than the image size—about 1/4 inch on each side—to hold the image in place without falling through.
3. Frame Size (Opening Size)
This is the inner dimension of the frame – the space where your image (with or without a mat) will sit. When a frame is labeled as 8x10 inches, it means it will hold an image (or mat) that is 8 inches by 10 inches.
4. Outer Frame Dimensions
This is the total width and height of the entire frame, including the molding. This measurement is important when you’re planning how much wall space the frame will occupy.
To measure accurately, gather these tools:
A tape measure or a ruler
The picture, photo or artwork you want to frame
Any existing matting (if applicable)
A notepad for recording dimensions
Step 1: Measure Your Image
Lay your artwork or photograph on a flat surface. Use a ruler or measuring tape to measure the width and height of the image. Be precise, especially if the artwork has borders or a signature you want visible.
Tip: If the edges are uneven or you want a border around the image, make note of the visible area you want displayed.
Step 2: Decide Whether to Use a Mat
If you plan to use a mat, decide how wide the mat border should be. Most standard mat widths are between 1.5 to 3 inches. Remember that the mat opening should be slightly smaller than the image so the artwork doesn’t fall through.
Example: For an 8x10 image, the mat opening might be 7.75" x 9.75".
Step 3: Determine the Frame Opening Size
The frame opening should match the image size or the mat outer size, depending on whether you're using a mat. This is the size you'll shop for when buying a frame.
Note: This measurement refers to the area inside the frame – not including the molding.
Step 4: Measure the Outer Frame Dimensions (Optional)
If you're working with an existing frame or planning wall layout, measure the full outer dimensions. This helps you determine how much wall space the frame will cover.
To do this, measure from the outer edges of the molding (width and height).
Double-check measurements: Especially when ordering custom frames online. A 1/4-inch error can affect the final presentation.
Communicate clearly: When ordering, specify whether your dimensions refer to image size, mat size or outer frame size.
Consider frame depth: If your artwork is thick (canvas, fabric, etc.), make sure the frame’s rabbet (depth inside the molding) can accommodate it.
Q: Should I measure the image or the existing frame?
A: Always measure the image or artwork you want to frame. Frames vary, and relying on an old frame’s size may not give you the best fit for new art.
Q: What if my artwork is an irregular shape?
A: You can either custom cut a mat to fit the shape or have a custom frame made to the exact size of your artwork.
Q: Can I trim my image to fit the frame?
A: It’s possible but not recommended unless you're sure the edges aren’t important. A mat is a better way to adjust the visible area without cutting.
Measuring a picture frame properly is the first step to creating a polished and visually pleasing display. By understanding the difference between image size, mat size and frame size, you can confidently select the right frame for your artwork or photo. Whether you’re designing a gallery wall, framing a cherished family photo or protecting a valuable print, accurate measurements make all the difference.
At Framorey, we believe in framing that combines style, precision and craftsmanship. If you’re unsure about your frame size or want a custom solution, our expert team is here to help. Browse our collection or reach out for personalized framing advice.