How to Calculate Cut Length for Pleated Drapes
Determining the correct cut length is one of the most critical steps in drapery fabrication. Even experienced workrooms can lose accuracy if they don’t follow a consistent method. This guide breaks down the exact formula professionals use to calculate cut length for pinch pleats, goblet pleats, cartridge pleats, and other structured drapery styles.
What Is Cut Length?
The cut length is the total length of fabric required for each drapery panel before adding pleats, hems, or finishing. It includes the finished length plus all allowances needed for workroom construction.
Getting the cut length precise ensures consistent panel drop, proper pleat alignment, and a clean break at the floor.
The Professional Cut Length Formula
Every workroom uses a slight variation, but the industry-standard formula is:
Cut Length = Finished Length + Header Allowance + Bottom Hem Allowance
Additional allowances may be needed for pattern match, banding, or weighted hems.
1. Determine Your Finished Length
The finished length is measured from the eye of the drapery hook (or top of the drapery if using a non-hook system) to the desired endpoint:
- Sill length: ½" above the sill
- Floor length: grazing or ½" above the floor
- Puddled: add 2–4" depending on style
2. Add Header Allowance
Header allowance depends on pleat type and the workroom’s construction method.
| Pleat Type | Typical Header Allowance |
|---|---|
| Pinch Pleat | 4"–5" |
| Goblet Pleat | 5"–6" |
| Cartridge Pleat | 4"–5" |
| Ripplefold (track systems) | Varies by carrier; typically 1½"–3" |
The header allowance includes the fabric needed for buckram, pleat construction, and the turn-under for a clean header finish.
3. Add Bottom Hem Allowance
The bottom hem must provide weight, stability, and a professional drop. Most workrooms use:
- Double 4" hem (8" total): most common
- Double 5" or 6" hem: for heavy linens or velvets
- Blind hem: on sheers or lightweight fabrics
4. Account for Pattern Repeat (If Applicable)
When working with printed or woven patterns, add the vertical repeat to match the motif across all panels.
Cut Length with Pattern Repeat = Base Cut Length + Full Vertical Repeat
Never split a repeat. Always round up to the next full repeat to avoid mismatched motifs.
Example: Calculating Cut Length
Project: Pinch pleat drapery, floor length
- Finished length: 96"
- Header allowance: 5"
- Bottom hem allowance: 8"
- Pattern repeat: 13" (rounded to full repeat)
Cut Length = 96" + 5" + 8" + 13" = 122"
Each panel should be cut at 122" before pleating and finishing.
Professional Tips
- Measure from the hook eye, not the top of the buckram.
- For puddled styles, add extra length at the finished measurement—not the header.
- Heavier fabrics require larger hems for a clean vertical hang.
- Always calculate cut length before determining fullness yardage.
Pro Tip: The EZ Pleating Curtain Calculator automatically applies header, hem, and repeat allowances for flawless workroom accuracy.
Mastering cut length calculations improves efficiency, reduces errors, and ensures consistent drapery drop across every panel. With a standardized method, your workroom can produce precise, professional results every time.
