Roman Blind Calculator
Calculate Your Roman Blind Requirements
Enter your window measurements below to calculate fabric quantities, fold sizes, and rod spacing for your Roman blind.
How to Measure for Roman Blinds
Inside the Window Reveal
- Measure the width at the narrowest point and subtract 1cm for clearance
- Measure the height from the top of the reveal to the sill
- Check measurements at multiple points as windows aren’t always level
- Ensure adequate clearance from window handles
Outside the Window Reveal
- Position the blind 10cm above the reveal for best appearance
- Extend 5-15cm below the sill for optimal light control
- Add 5-10cm to each side of the window width
- Consider existing window treatments when positioning
Roman Blind Fold Calculations
The number of folds in your Roman blind affects both its appearance and functionality. Here’s how to determine the optimal fold configuration:
Standard Fold Guidelines
| Blind Length | Recommended Folds | Fold Size Range |
|---|---|---|
| Up to 100cm | 3-4 folds | 16-25cm |
| 100-150cm | 4-6 folds | 18-25cm |
| 150-200cm | 6-8 folds | 20-25cm |
| Over 200cm | 8+ folds | 22-28cm |
Fabric Calculation Explained
Our calculator includes essential allowances for professional results:
Standard Allowances
- Side turnings: 8cm (4cm each side) for neat edges
- Top heading: 7.5cm for mounting system
- Bottom hem: 5cm for weight and stability
- Rod pockets: 2cm per pocket for dowel insertion
Pattern Repeat Considerations
- Additional fabric may be required to match patterns
- Centre the pattern for best visual impact
- Consider pattern direction when cutting fabric
- Allow extra fabric for pattern matching across joins
Rod Positioning Guide
Proper rod placement is crucial for even folds and smooth operation:
Rod Spacing Rules
- First rod positioned at half-fold distance from bottom
- Subsequent rods placed at full fold intervals
- Maximum spacing between lifting cords: 35cm
- Minimum of 2 lifting cords for blinds over 60cm wide
Cord Drop Calculations
The number of cord drops depends on your blind width:
- Up to 60cm: 2 cord drops minimum
- 60-120cm: 3 cord drops
- 120-180cm: 4-5 cord drops
- Over 180cm: 6+ cord drops for even lifting
Types of Roman Blinds
Standard Roman Blinds
Feature horizontal rods that create neat, even folds when raised. The fabric stacks uniformly with each fold sitting behind the previous one.
Cascading Roman Blinds
Create a waterfall effect with each fold slightly longer than the one above. This style adds elegant depth and visual interest to your window treatment.
Hobbled Roman Blinds
Maintain permanent soft folds even when fully extended, created by excess fabric between each rod. This creates a more relaxed, informal appearance.
Frequently Asked Questions
What fabric weight is best for Roman blinds?
Medium-weight fabrics (200-400gsm) work best as they hold their shape whilst folding cleanly. Avoid very heavy fabrics which may strain the mechanism.
Can I use patterned fabric for Roman blinds?
Absolutely! Consider pattern scale and repeat. Large patterns may require careful positioning, whilst small repeating patterns are more forgiving.
How do I calculate fabric for a joined blind?
When your blind width exceeds fabric width, you’ll need joins. Add 2cm seam allowance for each join and consider pattern matching requirements.
What’s the difference between recess and face-fix mounting?
Recess mounting fits inside the window reveal for a neat finish. Face-fix mounting attaches to the wall or window frame, allowing better light control.
How much extra fabric should I order?
Order 10-15% extra fabric to account for cutting errors, pattern matching, and potential future repairs or adjustments.
What tools do I need for installation?
You’ll need a drill, screwdrivers, spirit level, tape measure, pencil, and appropriate wall plugs for your wall type.
Professional Installation Tips
Pre-Installation Checklist
- Check wall structure and choose appropriate fixings
- Ensure mounting surface is level and secure
- Test mechanism operation before final installation
- Position brackets correctly for smooth blind operation
Common Installation Mistakes
- Insufficient bracket support causing sagging
- Incorrect cord routing leading to operational issues
- Poor rod pocket alignment affecting fold uniformity
- Inadequate clearance causing binding or rubbing