United Kingdom · en-GB
Roman Blind Calculator
Plan standard and cascade roman blinds from a recess or exact measurement. The core calculator runs in your browser and stays free to print. The optional AI helper sends only the room note you choose to submit.
Planning result
Estimation disclaimer. Figures are a transparent planning estimate for fabric and component quantities. They are not a trade cutting ticket and are not presented as workroom-accurate. Confirm allowances with your fabric, lining, headrail system and maker before cutting.
Finished 1090 mm × 1395 mm · 6 folds · face 1.52 m
Planning result updated: finished 1090 mm by 1395 mm, 6 folds, face fabric 1.52 metres.
From your measurement to the planning sheet
Input and fit adjustment
Opening entered: 1100 mm × 1400 mm. Recess clearances of 10 mm wide and 5 mm drop are deducted.
Finished rectangle
Finished blind: 1090 mm wide × 1395 mm drop.
Cutting rectangles
- Face cut
- 1190 mm × 1525 mm
- Lining cut
- 1130 mm × 1435 mm
The face width includes two 50 mm side turnings. Its drop starts at 1525 mm after the documented hem, top allowance.
Folds and hardware
6 folds place 6 rods at a planning length of 1070 mm. 4 cord columns are set from 80 mm in from each edge, at 310 mm spacing.
- Finished width
- 1090 mm
- Finished drop
- 1395 mm
- Face cut width
- 1190 mm
- Face cut drop
- 1525 mm
- Lining cut width
- 1130 mm
- Lining cut drop
- 1435 mm
- Fold count
- 6
- Fold size
- 215 mm
- Bottom section
- 322 mm
- Raised stack (estimate)
- 72 mm
- Rods
- 6 × 1070 mm
- Rings / cord
- 24 rings · 13940 mm cord
- Recess fit deducts the width and drop clearances from the opening measurements. Headrail thickness is not deducted separately.
Diagrams
The drawings follow the same baseline arithmetic as the numbers. They are planning sketches, not pattern pieces.
The rectangle is the finished blind. Face cut: 1190 mm × 1525 mm. Rings sit at every rod and cord column; fold lines mark the rod positions, including the longer bottom section.
The face hangs flat. Extra fabric is only the documented hems and top allowance. Lining cut: 1130 mm × 1435 mm.
| Rod | From bottom |
|---|---|
| 1 | 0 mm |
| 2 | 322 mm |
| 3 | 537 mm |
| 4 | 751 mm |
| 5 | 966 mm |
| 6 | 1180 mm |
| Column | From left |
|---|---|
| 1 | 80 mm |
| 2 | 390 mm |
| 3 | 700 mm |
| 4 | 1010 mm |
Professional job-pack preview
Optional labels below stay in the browser until you print or copy. Google sign-in temporarily saves them in this tab for a single return; and they do not create a job in any workroom system.
WorkroomCalc planning sheet
Model workroomcalc-baseline-2026-08-21 ·
Estimate only · not a signed cutting ticket
- Client / room
- —
- Face fabric
- —
- Lining
- —
- Headrail
- —
- Style
- standard
- Mount
- recess
- Finished width
- 1090 mm
- Finished drop
- 1395 mm
| Piece | Width | Drop | Length |
|---|---|---|---|
| Face fabric | 1190 mm | 1525 mm | 1.52 m |
| Lining | 1130 mm | 1435 mm | 1.44 m |
| Headrail / hook-and-loop | 1090 mm | — | — |
| Rods | 1070 mm | — | 6 rods |
Rings: 24. Total cord (planning): 13940 mm. Pull right.
Window project list
Build a list of windows from this calculator. Each added window keeps its own measurements and allowances. The list stays in this tab. Google sign-in temporarily saves it locally for one return; it is not sent to a model.
Add only identical blinds together. Different dimensions, fabric or allowances need a separate row.
No windows added yet.
How the estimate is built
Model workroomcalc-baseline-2026-08-21 uses documented planner allowances and school-level geometry. It does not copy a commercial workroom formula. Full constants, algebra and test vectors live in the project document docs/formula-provenance.md.
- Finished size equals the opening minus recess clearances, or the exact figures you typed.
- Fold count is the drop divided by the target fold size, clamped between 3 and 15. The bottom section is one and a half folds so the lowest panel hangs slightly longer.
- Face cut width is finished width plus a side turning on each side. Face cut drop is finished drop plus bottom hem, top allowance, and cascade extra when that style is selected.
- Cord columns are placed from each edge inset, then spaced no wider than the maximum column spacing where the cap of eight columns allows.
How to use the Roman blind calculator
Start with a careful width and drop measurement. Select recess fit when your figures describe the opening and you want the calculator to apply small fitting clearances. Select exact fit when your figures already describe the intended finished blind size. The separate roman blind measurement guide explains where to take each measurement and why checking the opening in several places matters.
Choose a standard blind for a flat lowered face, or cascade when you want soft folds to remain visible. Cascade construction consumes extra drop, so its face and lining requirements are larger. The default allowances are deliberately visible and editable: open the allowance panel to match the side turnings, bottom hem, top fixing method, fabric width, pattern repeat and cord layout used for your project.
Read the finished size first, then check the face and lining cut dimensions, rod length, ring count and estimated cord. A pattern repeat greater than zero rounds the face drop up to a complete repeat. If the cut width exceeds the entered fabric-roll width, the result warns that a join may be required. Print the planning sheet only after checking the figures against the fabric supplier, lining, headrail instructions and your own making method.
Common questions
What does this calculator estimate?
It estimates finished size, fold layout, face and lining cuts, rods, rings and cord from the measurements you type. The arithmetic is documented in the methods section.
Is this trade-accurate?
No. The figures are a transparent planning estimate. They are not a workroom cutting ticket and should be checked against fabric, lining, headrail and maker allowances before cutting.
Do I need an account or payment?
No. Calculation and printing stay free. Local tools need no account. Optional AI uses a Google-only account. Sign in with Google to check available AI credits and purchases in your account.