How to measure a bed for edging
The most accurate way is the simplest. Lay a garden hose or rope along the line you want, shape it until it looks right, mark where it ends, then pull it straight and measure it. That catches every curve, which a rectangle drawn around the bed cannot do. Choose the measured option and enter that length.
For a plain shape, the calculator can work out the edge. A circle is pi times the distance across. Be careful with something like a 16 foot circle, since people use that for the distance across and for the distance from the center, and the answers differ by double. An oval has no simple exact sum, so this uses Ramanujan's approximation as MathWorld prints it.
Then read your product's guide. Avon Plastics and Master Mark both say stakes every 4 feet on straight runs and every 2 feet on curves. Valley View says every 3 feet on one tall product, with extra on curves. Rolls and pieces vary too, and we read no guide that gives a standard length, so take that number from your label.
A worked example
Here is a circular bed 16 feet across with 20 foot pieces and stakes every 2 feet. These lines come from the same formula the calculator above runs.
Circle 16 ft across, 20 ft pieces
- 3.1416 × 16 = 50.27 ft of edge
- With 5 percent extra: 52.8 ft
- 20 ft less a 6 in overlap leaves 19.5 ft a piece, so 3 pieces
- 50.27 ÷ 2 = 25.13, so 26 stakes
The stake count treats the bed as a closed loop, which meets its first stake. A run with two ends needs one more. For an oval 10 feet long and 6 feet wide, the edge comes to 25.53 feet. Once the edging is in, the mulch calculator fills the bed, and the paver calculator covers a path next to it.
Edging for a circular bed
These use 20 foot pieces with a 6 inch overlap and our 5 percent extra. Measure the piece or roll you are buying, since other lengths give other counts.
| Distance across | Edge | With 5% extra | 20 ft pieces | Stakes at 2 ft |
|---|---|---|---|---|
| 4 ft | 12.6 ft | 13.2 ft | 1 | 7 |
| 6 ft | 18.8 ft | 19.8 ft | 2 | 10 |
| 8 ft | 25.1 ft | 26.4 ft | 2 | 13 |
| 10 ft | 31.4 ft | 33.0 ft | 2 | 16 |
| 12 ft | 37.7 ft | 39.6 ft | 3 | 19 |
| 16 ft | 50.3 ft | 52.8 ft | 3 | 26 |
| 20 ft | 62.8 ft | 66.0 ft | 4 | 32 |
Mistakes when buying edging
- Measuring a box around the bed. A rectangle's edge does not follow a curve. Use a hose.
- Confusing the size of a circle. A 16 foot circle may be 16 feet across or 16 feet from the center, which doubles the answer.
- Forgetting the overlap. Master Mark says to overlap the ends of strips when joining, so each piece gives less than its length.
- Too few stakes on curves. Two makers say every 2 feet on curves, and Master Mark says soil can call for more.
- A shallow trench. Master Mark says the trench should be at least half the height of the edging.
Questions
How much landscape edging do I need?
The bed's edge plus a little for trimming. Lay a hose or rope along the line, then measure it, as that catches every curve. For a plain shape, the calculator works out the edge for you. Add about 5 percent, which is our own figure.
How much edging do I need for a circle?
Pi times the distance across. A circle 10 feet across has about 31.4 feet of edge. Measure across the middle, or from the center out and double it. Add a little for trimming, and allow for overlap wherever two pieces join.
How much edging do I need for a 16 foot circle?
About 50.3 feet if 16 feet is the distance across, and about 100.5 feet if 16 feet is from the center to the edge. People use it both ways, so check which yours is. The calculator asks for the distance across.
How do I measure a curved bed for edging?
Lay a garden hose or rope along the line you want, mark where it ends and pull it straight to measure it. Do not measure a rectangle around the bed, as that does not track the curve. Then choose the option for a length you measured.
How many stakes per foot?
One every 4 feet on a straight run and one every 2 feet on curves, by Avon Plastics and Master Mark. Valley View says every 3 feet on its tall edging. Master Mark also says curves or soil may call for more, so follow your own guide.
How deep should edging go?
At least half its height in the trench, by Master Mark. Edging 4 inches tall would sit at least 2 inches in the ground. Other products have their own guides, so read yours before you dig, especially for tall edging.
This landscape edging amount is an estimate, and only the geometry is exact. Stake needs change with the product and the soil, so follow the label or install guide for yours, as makers differ. The allowance and overlap are our own numbers, as no maker we read gives one. A hose laid along a real curve beats any shape picked here.
Sources and review
- Classic landscape edging install guide, Avon Plastics, no date printed, file details 2024.
- Terrace Board woodgrain edging guide, Master Mark, no date printed, file details 2024.
- Terrace Board edging install guide, Master Mark, no date shown, read November 2026.
- Tall edging install sheet, Valley View Industries, no date printed, file details 2020.
- Ellipse, in MathWorld, Wolfram MathWorld, updated 2026.
Checked in November 2026. Spotted a wrong number? Report it and it goes in the corrections log.
How this is calculated
Every figure below is read from the code that produces the answer, so what is written here is what the calculator ran. The constants were last checked against their sources in November 2026.
The arithmetic
Circle
Edge = 3.1416 × Distance across
- 3.1416
- Pi, to four places
Worked through: 3.1416 × 16 = 50.27 ft
Oval
Edge = 3.1416 × (3(a + b) less the square root of (a + 3b)(3a + b))
- a and b
- Half the oval's length and half its width
Worked through: 3.1416 × 8.1255 = 25.53 ft
The constants, and where they come from
STRAIGHT_STAKE_SPACING_FEET
Published figureFeet between stakes on a straight run
Applies to: Plastic edging from these makers. Follow your own product's guide where it differs
Source: Classic landscape edging install guide, Avon Plastics, published 2024-12, read 2026-11. This source is about 2 years old, and it is the one the figure rests on.
Also from: Terrace Board woodgrain edging guide, Master Mark, published 2024-03, read 2026-11.
Also from: Terrace Board edging install guide, Master Mark, no date on the page, read 2026-11.
Avon Plastics says every 4 feet and every 2 feet for curves. Master Mark's newer Terrace Board guide agrees, and its older one gives every 4 feet.
CURVED_STAKE_SPACING_FEET
Published figureFeet between stakes on a curve
Applies to: Plastic edging from these makers. Follow your own product's guide where it differs
Source: Classic landscape edging install guide, Avon Plastics, published 2024-12, read 2026-11. This source is about 2 years old, and it is the one the figure rests on.
Also from: Terrace Board woodgrain edging guide, Master Mark, published 2024-03, read 2026-11.
Master Mark also says some designs may need more stakes, because of curves or soil conditions, so this spacing is a starting point.
OTHER_STAKE_SPACING_FEET
Published range, narrowedFeet between stakes on one tall edging product
Applies to: Valley View's tall edging
Source: Tall edging install sheet, Valley View Industries, published 2020-06, read 2026-11. This source is about 6 years old, and it is the one the figure rests on.
This sheet says every 3 feet, with extra stakes on curves, and shows every 2 feet for another variant in the same file.
DEFAULT_ALLOWANCE_PERCENT
ModelledExtra added for trimming and for curves you did not catch
Applies to: Our own assumption, which you can change
No published figure exists for this. It is derived, and the derivation is below rather than a citation to something that does not say it. Last checked in November 2026.
No manufacturer we read states an allowance. We saw 5 to 10 percent only in search summaries of low-authority calculators, so we took the low end.
DEFAULT_OVERLAP_INCHES
Modelled from published dataInches lost at each join between pieces
Applies to: Our own figure, which you can change
Source: Terrace Board woodgrain edging guide, Master Mark, published 2024-03, read 2026-11. This source is about 2 years old, and it is the one the figure rests on.
Master Mark says to overlap the ends when joining strips, and gives no length. Six inches is our own starting point and not a maker's number.
INCHES_PER_FOOT
DefinitionalInches in one foot
Applies to: Definitional, everywhere
True by definition, so there is nothing to cite. The derivation is below.
Twelve inches make a foot by definition, so the overlap in inches is divided by 12 before it comes off a piece's length in feet.
What the labels mean
- Published figure:
- taken directly from the source named beside it.
- Published range, narrowed:
- a source publishes a range and this calculator uses a representative value from it.
- Modelled:
- derived rather than measured, and the derivation is shown.
- Modelled from published data:
- derived rather than measured, calibrated against the source named beside it.
- Definitional:
- true by definition, like the number of inches in a foot, so there is nothing to cite.
If a figure here looks wrong, it may be. Tell us what you found and we will check it against the source and publish a correction if it needs one. How constants are chosen and how often they are reviewed is set out in our methodology.
How to use the landscape edging calculator
- 1
Choose the shape, or lay a hose along the line and measure it
- 2
Choose how often the stakes go
- 3
Read your piece or roll length from the label
- 4
Check the extra for trimming and the overlap
- 5
Buy what it shows, and keep the spare stakes for curves
What this calculator assumes
Every estimate here rests on the assumptions below. Where your job differs from one of them, the figure will differ too.
- Oval edges use Ramanujan's approximation, which is close to exact
- Stakes go at the spacing you choose, over the bed's measured length
- A closed loop meets its first stake, and an open run needs one more
- A 5 percent allowance and a 6 inch overlap are our own assumptions
Pro tips
- Lay a hose along the line to see it before you dig
- Keep the trench at least half the edging's height
- Buy a few spare stakes for tight curves