Formula Used
| Shape | Area formula | Perimeter formula |
|---|---|---|
| Rectangle | length × width | 2(length + width) |
| Square | side² | 4 × side |
| Circle | πr² | 2πr |
| Semicircle | ½πr² | πr + 2r |
| Ellipse | πab | Ramanujan approximation |
| Triangle | ½ × base × height | sum of three sides |
| Trapezoid | ½(a + b)h | sum of four sides |
| L-shape | outer rectangle − cut-out rectangle | outer boundary measurement |
| Ring | π(R² − r²) | 2π(R + r) |
Material volume equals adjusted area multiplied by material depth. Package totals always round upward to complete purchasable units. Cost totals use the quantities entered above.
How to Use
- Select one input unit and one area result unit.
- Add every flower bed and choose its matching shape.
- Enter the displayed dimensions for each bed.
- Add paths, rocks, trees, or other excluded spaces.
- Enter spacing, material depths, packaging, and costs.
- Submit the form and review each calculated result.
Measure the longest usable dimensions for every flower bed. Divide irregular beds into smaller measured sections before entering them. Keep all main bed measurements in one selected unit.
Example Data
| Input | Example value | Purpose |
|---|---|---|
| Main bed | 12 ft × 6 ft | Rectangle area and perimeter |
| Tree exclusion | 1.5 ft radius | Subtract unplantable space |
| Plant spacing | 30 cm × 30 cm | Estimate plant count |
| Mulch depth | 7.5 cm | Estimate volume and bags |
| Area overage | 5% | Allow for measurement variation |
Frequently Asked Questions
Can this calculator handle multiple flower beds?
Yes. Add as many beds as required. Their areas and perimeters are totalled automatically.
How do I measure an irregular flower bed?
Divide it into smaller rectangles or measured sections. Enter up to four section areas. Add the measured outer perimeter separately.
Can I subtract a path or tree?
Yes. Add each obstacle as an excluded area. The calculator removes it from usable planting area.
How is an ellipse measured?
Enter the complete longest and shortest diameters. The calculator divides them into semi-axes. It then applies the ellipse formula.
Why does the plant count round upward?
Plants are purchased as whole units. The loss allowance also covers replacements. This reduces shortages during planting.
What does triangular spacing change?
Triangular spacing fits more plants into equal area. The calculator applies a density factor. Actual layouts may require minor adjustment.
How are mulch bags calculated?
Area is multiplied by depth and allowances. Volume converts into litres. Bag totals round upward to complete bags.
Can it calculate bulk material?
Yes. Results include litres and cubic metres. These values support bagged or bulk purchasing.
Does edging include internal obstacles?
It can. Select the obstacle-border option when needed. Otherwise only external flower bed boundaries are used.
Are project costs exact?
No. Costs depend on entered prices and package sizes. Supplier pricing and installation conditions may differ.
Can I export the results?
Yes. Copy, share, print, CSV, and PDF controls appear after calculation. Browser support may vary for sharing.