Inputs
Example Data Table
These examples show how typical inputs affect recommended umbrella size.
| Scenario | Shaded object | Key inputs | Suggested size | Base weight |
|---|---|---|---|---|
| Patio round set | Round table | Diameter 1.20 m, margin 0.60 m, medium wind | 2.44 m canopy | ~25 kg |
| Outdoor dining | Rectangle table | 1.80 m × 0.90 m, margin 0.60 m, medium wind | 3.05 m canopy | ~30 kg |
| Garden bed shade | Zone by area | Area 8.0 m², full coverage, low wind | 3.35 m canopy | ~35 kg |
| Open, windy spot | Round table | Diameter 1.20 m, margin 0.60 m, high wind | 2.74 m canopy | ~47 kg |
Formula Used
This calculator sizes a round canopy that comfortably covers your space.
1) Choose a base dimension
- Round table: Base = table diameter
- Square table: Base = side length
- Rectangle table: Base = max(length, width)
- Zone by area: Base = 2 × √(Area ÷ π)
2) Add shade margin (overhang)
Recommended canopy diameter:
Drec = Base × SeatFactor + 2 × Margin
SeatFactor gently increases size for larger groups. A standard-size canopy is then chosen at or above Drec.
3) Coverage area
Canopy area (round):
A = π × (D ÷ 2)²
4) Base weight guidance
Base weight uses size tiers, then applies multipliers for wind exposure and cantilever designs. Always follow manufacturer limits and local conditions.
How to Use This Calculator
- Select your units and what you want to shade.
- Enter the table dimensions or the target area.
- Set the shade margin for extra overhang.
- Choose wind exposure and umbrella type.
- Click Calculate to see results above the form.
- Download CSV or PDF for records and purchasing.
For windy gardens, consider vented canopies, tilt locks, and sturdier poles. Store umbrellas closed when not in use to extend fabric life.