Free Costume Planning Tool
Panel & Seam Allowance Calculator
What This Solves
What does this panel calculator solve?
A lot of costume pieces start as simple panels: overskirts, lining pieces, hanging tabs, banners, cape panels, and casing-based pieces. This tool helps you add the allowances that are easy to forget while also checking how efficiently those panels fit across the bolt.
Quick Start
Best way to use it
- 1Enter the finished width and height you actually want to see in the final project.
- 2Add seam, hem, and top allowances based on your construction method.
- 3Set the fabric width and number of matching panels.
- 4Use the cut size and total length outputs to plan purchases and cutting order.
Panel Planning Inputs
Live Results
Cutting Results
Use case: This is especially handy when you already know your finished panel size and just need shopping and cutting numbers quickly.
Share these results with your shopping buddy or save the summary before you head to the store.
Verify results before use. See our disclaimer.
Frequently Asked Questions
Keep Planning
What's Next?
Use the next calculator while your measurements, notes, and shopping list are still in front of you.
Resource Guide
Why simple panel math deserves its own calculator
Finished measurements are easy to talk about and easy to forget when you start cutting. The moment seam allowances, deep hems, casings, and multiple panels enter the picture, the cut size can be noticeably larger than the finished size.
This is the fastest way to avoid small but expensive mistakes
A half inch forgotten on both sides of multiple panels adds up quickly, especially in expensive coatings, satins, wool blends, or limited cosplay prints. This tool is most valuable on projects where the shapes are straightforward but the allowance stack is not.
Use it as a bridge between concept and yardage
Sometimes you know the finished panel dimensions before you know the full garment layout. In that case, panel math becomes the bridge between the idea and the shopping list. Once the panel sizes are correct, you can move on to yardage, trim, or pricing with less guesswork.
Live Results
Cutting Results
Use case: This is especially handy when you already know your finished panel size and just need shopping and cutting numbers quickly.
Share these results with your shopping buddy or save the summary before you head to the store.
Verify results before use. See our disclaimer.