Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Sewing
Zipper Length Calculator
Compute the minimum zipper length to buy for a given opening length and zipper type, accounting for slider parking and stop placement. Useful when shopping zippers before starting construction so you do not buy short.
Fill in the required fields to see your result.
Sewing
Seam Allowance Calculator
Calculate the total cut fabric area needed when adding seam allowances to a target finished size. Use it when drafting patterns, adjusting existing patterns, or estimating fabric for projects where the seam allowance reduces the finished dimensions.
Fill in the required fields to see your result.
Key differences
| Zipper Length Calculator | Seam Allowance Calculator | |
|---|---|---|
| Category | Sewing | Sewing |
| Inputs required | 2 | 3 |
| Result | Recommended Zipper Length (inches) | Total Fabric Area (square inches) |
| What it does | Compute the minimum zipper length to buy for a given opening length and zipper type, accounting for slider parking and stop placement. Useful when shopping zippers before starting construction so you do not buy short. | Calculate the total cut fabric area needed when adding seam allowances to a target finished size. Use it when drafting patterns, adjusting existing patterns, or estimating fabric for projects where the seam allowance reduces the finished dimensions. |