Calculator Inputs
Example Data Table
| Door type | Opening (W×H) | Panel width | Handle projection | Side clearance required | Head clearance required |
|---|---|---|---|---|---|
| Single sliding | 1800×2100 mm | 900 mm | 25 mm | ~1000 mm | ~68 mm |
| Bi-parting | 2400×2100 mm | 1200 mm | 30 mm | ~1300 mm (each side) | ~70 mm |
| Bypass (3 panels) | 2700×2100 mm | 900 mm | 25 mm | ~1900 mm | ~68 mm |
Formula Used
1) Side clearance (stacking/pocket space):
Single: Side Required = (1 × Panel Width) + Overlap + Jamb Clearance + Travel Stop + Handle Projection + 2×Weather Allowance
Bi-parting (per side): Side Required = (1 × Panel Width) + (Overlap ÷ 2) + Jamb Clearance + Travel Stop + Handle Projection + 2×Weather Allowance
Bypass: Side Required = ((Panels − 1) × Panel Width) + Overlap + Jamb Clearance + Travel Stop + Handle Projection + 2×Weather Allowance
2) Head clearance: Head Required = Track Height + Mounting Gap + Top Buffer
3) Bottom clearance: Bottom Required = Bottom Clearance + Floor Variation Buffer
4) Front clearance: Front Required = Panel Thickness + Handle Projection + Front Safety Buffer
How to Use This Calculator
- Choose units that match your tape measure.
- Select the door type and enter opening dimensions.
- Enter panel width, thickness, and the handle projection.
- Add overlap and clearances for smooth outdoor movement.
- Optional: add available stack-side space to verify fit.
- Click calculate to see required clearances and downloads.
Why sliding clearances matter in garden spaces
Garden-facing sliders often work harder than interior doors. Wind, dust, moisture, and soil movement can push frames out of square. Clearance planning prevents rubbing, sticking, and premature roller wear, especially near patios, pergolas, and greenhouse entries. A few millimeters of allowance can protect finishes and keep access smooth during wet seasons. Measure the opening at three points and use the smallest reading. Check finished surfaces, not subfloor, and note any trim or trellis projections that reduce travel space along the stack side.
Choosing the right door layout for access flow
Single sliding suits narrow paths when one clear opening direction is enough. Bi-parting improves traffic at wide openings, useful for moving pots, wheelbarrows, or harvest crates. Bypass systems help when fixed walls limit pocket space, but they increase track complexity and demand consistent alignment across multiple panels.
Interpreting side, head, bottom, and front clearance outputs
Side clearance estimates how far panels must travel to fully open without hitting planters, fences, or posts. Head clearance accounts for track height, mounting hardware, and a top buffer to avoid binding. Bottom clearance includes a floor variation buffer for pavers and drainage. Front clearance helps keep handles from crowding walkways and raised beds.
Outdoor factors that change real-world clearances
Humidity and temperature swings can cause material expansion, so the weather allowance supports dependable movement year-round. Debris is common near gardens; increasing bottom clearance can reduce scraping over gravel, mulch, and leaves. If winds drive the panel toward a jamb, a slightly larger running clearance can improve glide while still controlling drafts.
Using exports for planning, procurement, and installation checks
Download the CSV to share input assumptions with installers, landscapers, or fabricators. The PDF captures the result summary for site walk-throughs and punch lists. Re-run scenarios for different handle types, overlaps, and stop buffers to confirm clear travel near beds, irrigation lines, and lighting fixtures before final placement.
FAQs
1) What units should I use for the most reliable result?
Use millimeters when possible. Smaller units reduce rounding and help when you are checking handle projections, track height, and tight pocket spaces near planters, edging, or posts.
2) Why does the calculator ask for handle projection?
Handles often strike walls, fences, or screens first. Adding projection helps estimate front clearance and side travel limits, preventing pinch points in narrow garden walkways.
3) When should I enter stack-side available space?
Enter it when a planter box, wall, trellis, or gate limits how far the panel can slide. The tool will show whether the provided distance meets the required travel space.
4) What does weather swell allowance represent?
It is a buffer for outdoor expansion and seasonal movement. Increasing it can improve reliability in humid or hot climates, especially for doors exposed to rain or direct sun.
5) Can the results replace manufacturer installation instructions?
No. Use the results for planning and clash detection. Always confirm final clearances, hardware limits, and structural requirements using the door system’s installation guide.
6) How do I reduce a clearance deficit on the stack side?
Choose a smaller panel width, reduce handle projection, adjust stop buffers, or switch to a different door layout. In some cases, moving nearby beds or posts provides the needed travel space.