Am I really sewing a 1/4 inch seam?


I have heard lots of advice given about making sure you are actually sewing a 1/4 inch seam. But how do you know? Do you really know?

Today I will show you how I measured my presser feet to see where the 1/4 inch actually hits them. 

The ruler I will using to measure is one of my cutting rulers. It is a clear plastic with a very clear 1/4 inch mark. 


First, I make sure the needle is in the center position.

I have the machine on for the light, but I carefully place the ruler under the presser foot and, using the hand crank, lower the needle so that it is close to the ruler without touching it.

Placing Ruler under the presser foot

I am very careful not to touch the foot controller because if the needle hits this ruler it will break and possibly hurt the machine in other ways. 

Here you can see my needle lined up the the 1/4 inch mark. You can also see where the end of the ruler hit the side of my 1/4 inch presser foot. It is just about lined up perfectly.  So when I sew, I need to make sure that is where my fabric lines up too. 

1/4 inch presser foot being measured

For fun, I thought I would see what a 1/4 inch looks like on two of the other feet I use quite frequently. 

My owner's manual classifies this as the Monogramming Foot. But it is what I use for general sewing and zig-zagging. You can see that the 1/4 inch hits about an 1/8th of an inch away from the edge of the foot. 

Presser foot being measured

This foot is called the zig zag foot. (Now I know!) This foot isn't as wide as the monogramming foot, but it is still pretty far off. 

Presser Foot Being Measured

Different machine and different manufacturers will have the 1/4 inch rest at slightly different positions. So it is important to test each machine and foot. 

This is how my 1/4 inch seam should look when I line up the fabric.

Sewing with a 1/4 inch seam with a 1/4 inch foot

Previously, I had been doing a lot of 1/4 inch seams at about here. 

Wrong use of 1/4 inch presser foot

Now there are a lot of patterns that will still turn out fine as long as you are consistent in your seams. A lot of patterns with squares and rectangles would be ok if you are off. But blocks that involve curves and triangle will get really far off and won't match up if you do not use the correct seam allowance. 

Being off a few threads doesn't seem like a lot. But that difference doubles with each seam because you are sewing two pieces of fabric together. Then that adds up for each seam you sew. Next thing you know, your quilt top is 4 inches too short for it's borders!

Your job for today? Go measure your presser feet!

Have fun quilting!

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