Hem Allowance Calculator for Cut Length
Add hem and seam allowances to a finished length to get the length to cut. Choose a double fold hem to fold the raw edge under twice for a clean finish.
How to add hem allowance
- Enter the finished length of the piece in inches.
- Set the hem allowance and tick double fold if the hem turns under twice.
- Add the seam allowance for the other end, then read the cut length.
Examples
28 inch finished with a 2 inch single hem and 5/8 inch seam
Finished 28 in, hem 2 in, seam 0.625 in
Total allowance 2.625 in, cut 30.625 in
Frequently asked questions
What is a double fold hem?
A double fold hem turns the raw edge under twice so no raw edge shows on the inside. Because the fabric folds up twice, it uses double the hem allowance compared with a single fold.
How much hem allowance should I add?
Around 1 inch suits light hems, with 2 to 3 inches for trousers, skirts and curtains. A wider hem hangs better on heavy fabric. Use a double fold for a tidy enclosed edge.
Why is 5/8 inch the default seam allowance?
Most garment patterns use a 5/8 inch, which is 0.625 inch, seam allowance as the standard. Change it to 1/4 inch for quilting or 1/2 inch for many home projects.
How is the cut length worked out?
The hem used is doubled for a double fold hem, then added to the seam allowance to get the total allowance. The cut length is the finished length plus that total allowance.
Does this cover both ends of the piece?
It adds one hem at one end and one seam allowance at the other. If both ends are hemmed, add a second hem allowance, or set the seam allowance to your second hem amount.
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