Calculator Inputs
Formula Used
- Area: A = L × W
- Width from area: W = A ÷ L
- Length from area: L = A ÷ W
- Perimeter (edging): P = 2(L + W)
- Diagonal: D = √(L² + W²)
- Soil volume (optional): V = A × Depth
Unit conversions are applied before calculations for consistent results.
How to Use This Calculator
- Select a calculation mode based on what you know.
- Pick your linear unit, then enter length and/or width.
- If using area, enter the area and choose its unit.
- Optionally add soil depth to estimate fill volume.
- Press Calculate to view results above the form.
- Use the export buttons to save CSV or PDF.
For accurate edging, include corners and join overlaps.
Example Data Table
Sample scenarios for planning common garden beds.
| Length | Width | Depth | Area | Edging | Soil Volume |
|---|---|---|---|---|---|
| 4.0 m | 1.2 m | 0.30 m | 4.80 sqm | 10.40 m | 1.44 m³ |
| 10.0 ft | 4.0 ft | 1.0 ft | 40.00 sqft | 28.00 ft | 40.00 ft³ |
| 3.0 m | 0.9 m | 0.20 m | 2.70 sqm | 7.80 m | 0.54 m³ |
Practical Guide to Bed Length and Width Planning
1) Why bed dimensions matter
Bed size drives planting density, irrigation coverage, and maintenance comfort. A common reach limit is about 0.45–0.60 m from each side, so many gardeners keep bed width near 0.9–1.2 m when access is available on both sides. Longer beds can improve row efficiency, but very long runs may need stepping stones or cross paths to prevent soil compaction.
2) Using area when space is fixed
When you know the available area, this calculator can solve a practical width or length that fits the site. For example, if you have 6.0 sqm beside a wall and choose a 3.0 m length, the computed width is 2.0 m. That width may be hard to reach, so you can iterate: increase length or split into two beds for easier access and better airflow.
3) Perimeter output for edging and borders
The perimeter result estimates edging length for timber, metal, blocks, or drip-line routing. Add 5–10% extra for overlaps, corner joints, and waste, especially when using rigid materials. For raised beds, accurate perimeter planning also helps you estimate fasteners, corner brackets, and liner lengths.
4) Soil volume with depth for raised beds
Soil volume is calculated from area and depth. A 4.8 sqm bed at 0.30 m depth needs about 1.44 m³ of soil, which is roughly 1,440 liters. Many suppliers sell soil by cubic meter or cubic foot, so the calculator reports multiple units to support ordering. Consider settling: loose soil can drop after watering, so ordering slightly more can avoid low spots.
5) Turning dimensions into planting layouts
Once length and width are set, you can map rows, square-foot grids, or blocks for crop rotation. The diagonal value helps confirm squareness during layout by checking corner-to-corner measurement. Use the exported CSV or PDF to share dimensions with installers, suppliers, or team members and keep records for seasonal planning.
FAQs
1) What bed width is easiest to maintain?
Many layouts use 0.9–1.2 m width when you can access both sides. This range supports comfortable reaching, reduces soil compaction, and simplifies harvesting and weeding.
2) Can I use this for raised beds?
Yes. Enter length and width as usual, then add an optional soil depth to estimate fill volume. This helps you order soil or growing mix in common supply units.
3) Why does the calculator show perimeter?
Perimeter estimates edging length for borders, timbers, blocks, or protective barriers. It also helps plan drip lines and landscape fabric cuts around the bed.
4) How accurate is the soil volume estimate?
It is a geometric estimate based on a rectangular shape and uniform depth. Real volumes vary with settling, moisture, and bed shape. Ordering 5–15% extra often prevents shortages.
5) What if my bed area is known but the shape is flexible?
Use Area & Length or Area & Width mode to solve the missing side, then adjust the chosen side until the shape is practical for reach, paths, and crop spacing.
6) Does diagonal measurement help during layout?
Yes. Checking the diagonal helps confirm corners are square. If both diagonals match on a marked rectangle, the layout is typically square and ready for edging or framing.
7) Which units should I use for best results?
Use the units you measure on site. The calculator converts internally for consistency. Choose linear units for tape measurements and area units that match your plan or supplier quotes.