---
title: "Landscape Edging Calculator: Stake Spacing, Linear Footage, and Thermal Bow Prevention"
canonical: "https://theyieldgrid.com/landscape-edging-calculator/"
model_id: "tyg-2759"
model_version: "1.0.0"
last_reviewed: "2026-08-20T10:20:07"
reviewed_by: "Umer Hayiat"
---

# Landscape Edging Calculator: Stake Spacing, Linear Footage, and Thermal Bow Prevention

> Canonical calculator: [https://theyieldgrid.com/landscape-edging-calculator/](https://theyieldgrid.com/landscape-edging-calculator/)

## What this calculator does

Home - Free Gardening Calculators & Tools - Landscape Edging Calculator: Stake Spacing, Linear Footage, and Thermal Bow Prevention Linear footage, stake count, and thermal expansion checks for steel, poly & stone edging.

## Inputs

| Input | ID | Type | Unit | Range or choices | Required |
|---|---|---|---|---|---|
| Garden Bed Shape * | `lec_shape` | select |  | — Select a shape — = ``; Circle = `circle`; Rectangle = `rectangle`; Kidney / Freeform = `kidney` | Yes |
| Radius (ft) * | `lec_radius` | number | ft | 0.5 to 500 | Yes |
| Length in feet | `lec_length` | number | feet | 0.5 to 10000 | Yes |
| Width in feet | `lec_width` | number | feet | 0.5 to 10000 | Yes |
| Estimated Perimeter (ft) * | `lec_kidney_perimeter` | number | ft | 1 to 10000 | Yes |
| Edging Material * | `lec_material` | select |  | — Select material — = ``; Poly Bender Board (plastic) = `poly`; Steel Edging = `steel`; Stone / Cobble Edging = `stone` | Yes |
| Soil Type * | `lec_soil` | select |  | — Select soil type — = ``; Soft / Sandy Soil = `soft`; Hard / Clay Soil = `hard` | Yes |

## Outputs

| Output ID | Default state |
|---|---|
| `lec_err_shape` | Required |
| `lec_err_radius` |  |
| `lec_err_length` |  |
| `lec_err_width` |  |
| `lec_err_kidney` |  |
| `lec_err_material` | Required |
| `lec_err_soil` | Required |
| `lec_results_panel` | Total Material Needed — linear ft Net perimeter vs. total with waste Net perimeter 10% waste allowance Net Perimeter — ft Stakes Required — stakes Stake Spacing — ft apart Warnings & Installation Standards Quick Reference: Stake Spacing by Scenario Scenario Material Spacing Stakes / 100 ft Recommended Products for This Install Col-Met Steel Landscape Edging 10″ Steel Landscape Spikes Half-Moon Edging Shovel Foam Knee Pads |
| `lec_out_primary` | — |
| `lec_out_perimeter` | — |
| `lec_out_stakes` | — |
| `lec_out_spacing` | — |
| `lec_warnings_box` | Warnings & Installation Standards |
| `lec_warnings_list` |  |

## Formula and method

Our algorithm automatically tightens stake intervals for curves under a five-foot radius to ensure structural integrity. Show the calculation steps Step 1: Compute the net perimeter by shape. Circle: Circumference = 2 x pi x Radius (pi = 3.14159). Result in feet. Rectangle: Perimeter = 2 x (Length + Width). Result in feet. Kidney / Freeform: Perimeter = user-supplied measured value in feet. No formula is applied; the calculator trusts this input directly. Step 2: Apply the 10 percent waste allowance. Total Linear Feet = Net Perimeter x 1.10. This accounts for end overlaps, corner cuts, damaged sections, and the buffer needed when joining sections mid-run. Round to one decimal place for the displayed result; order to the next full unit above this number. Step 3: Determine stake spacing by material and curve geometry. Poly bender board, straight or gentle curves (radius at or above 5 ft): 4 ft between stakes. Poly bender board, tight curves (radius under 5 ft) or any kidney/freeform bed: 1.5 ft between stakes. This is the thermal expansion safety requirement. Steel edging, any shape: 2.5 ft between stakes minimum. Stone / cobble edging: no stakes; set-in-place in a compacted sand or concrete base. Step 4: Compute stake count. Stakes = ceiling(Total Linear Feet / Stake Spacing) + 1. The ceiling function rounds up to the next whole number. The +1 adds the terminal end stake that closes the run. Step 5: Apply soil-type warnings. Soil type does not change the stake count formula. It triggers advisory warnings about installation technique and stake product selection. Hard clay: use 10-inch steel spikes, pre-soak, rubber mallet. Soft/sandy soil: standard plastic edging pins are sufficient for poly; steel stakes are still preferred for steel edging. Rounding rules: All perimeter and total footage values are rounded to one decimal place for display. Stake counts use ceiling rounding (always round up, never down). Assumptions and Limits The 10 percent waste factor is a fixed allowance. Highly irregular freeform beds or those requiring many short-section cuts may warrant ordering an additional 5 to 10 percent beyond the calculator’s output. The circle formula assumes a perfect geometric circle. Beds that are egg-shaped, elliptical, or otherwise non-circular will return an incorrect perimeter if the Circle input is used. Use Kidney/Freeform and measure the actual path instead. The tight-curve threshold of 5 ft radius is the point at which thermal bowing in poly becomes structurally significant under typical summer temperature swings. Beds with radii between 5 and 8 feet in dark-colored poly and high sun exposure may benefit from reducing spacing to 2 to 3 feet as a precaution. The stake count calculation assumes uniform spacing for the entire run. Real installations may have corner clusters or transition zones where spacing is tighter, which will slightly increase the actual stake count needed. Stone edging is treated as a no-stake product. Some cobble border systems use landscape pins for alignment; consult the product instructions if your stone system includes a pinning specification. This tool does not account for ground slope. Steeply sloped beds may require shorter stake intervals on the downhill face to resist lateral soil pressure and edging migration. Frost heave depth requirements for steel edging vary by USDA hardiness zone and local frost depth. The 1.5-inch minimum burial recommendation in the calculator’s warning panel is a general minimum, not a zone-specific engineering specification.

## Verified worked examples

### Example 1: Circular Rose Bed, Radius 6 Feet, Poly Bender Board, Soft Soil

Shape: Circle Radius: 6 ft Material: Poly bender board Soil: Soft / sandy Circumference = 2 x 3.14159 x 6 = 37.7 ft (rounded to one decimal). Total with 10 percent waste = 37.7 x 1.10 = 41.4 ft. Radius of 6 ft exceeds the 5-ft tight-curve threshold, so stake spacing is 4 ft. Stakes = ceiling(41.4 / 4) + 1 = 11 + 1 = 12 stakes . Result: 41.4 linear feet of poly edging, 12 stakes at 4-foot spacing. This is a manageable single-section install. The radius is just above the tight-curve cutoff, but any sections of the circle that were installed in a tighter arc than the overall radius (such as an indented portion of the bed) should receive an extra stake between the standard ones.

### Example 2: Rectangular Perennial Bed, 20 x 8 Feet, Steel Edging, Hard

Clay Shape: Rectangle Length: 20 ft Width: 8 ft Material: Steel edging Soil: Hard / clay Perimeter = 2 x (20 + 8) = 56 ft. Total with 10 percent waste = 56 x 1.10 = 61.6 ft. Steel stake spacing minimum = 2.5 ft. Stakes = ceiling(61.6 / 2.5) + 1 = 25 + 1 = 26 stakes . Result: 61.6 linear feet of steel edging, 26 stakes at 2.5-foot spacing. Hard clay requires pre-soaking the bed perimeter 12 to 24 hours before installation. Use a dead-blow rubber mallet rather than a standard hammer to avoid deforming the stake heads. Bury the lower lip at least 1.5 inches to prevent frost heave in climates with ground freeze.

### Example 3: Kidney/Freeform Island Bed, Estimated 80-Foot Perimeter,

Poly, Soft Soil Shape: Kidney / Freeform Estimated perimeter: 80 ft Material: Poly bender board Soil: Soft / sandy Net perimeter = 80 ft (user-measured). Total with 10 percent waste = 80 x 1.10 = 88 ft. Kidney/freeform beds trigger tight-curve staking (1.5 ft). Stakes = ceiling(88 / 1.5) + 1 = 59 + 1 = 60 stakes . Result: 88 linear feet of poly edging, 60 stakes at 1.5-foot spacing. Sixty stakes for an 88-foot run sounds aggressive, but this is the correct specification for any flexible poly material on a continuous curved path exposed to summer sun. Reducing this to 4-foot spacing to save money on stakes is the primary cause of the thermal bowing failure mode described in the warnings below.

## Assumptions

Our algorithm automatically tightens stake intervals for curves under a five-foot radius to ensure structural integrity. Show the calculation steps Step 1: Compute the net perimeter by shape. Circle: Circumference = 2 x pi x Radius (pi = 3.14159). Result in feet. Rectangle: Perimeter = 2 x (Length + Width). Result in feet. Kidney / Freeform: Perimeter = user-supplied measured value in feet. No formula is applied; the calculator trusts this input directly. Step 2: Apply the 10 percent waste allowance. Total Linear Feet = Net Perimeter x 1.10. This accounts for end overlaps, corner cuts, damaged sections, and the buffer needed when joining sections mid-run. Round to one decimal place for the displayed result; order to the next full unit above this number. Step 3: Determine stake spacing by material and curve geometry. Poly bender board, straight or gentle curves (radius at or above 5 ft): 4 ft between stakes. Poly bender board, tight curves (radius under 5 ft) or any kidney/freeform bed: 1.5 ft between stakes. This is the thermal expansion safety requirement. Steel edging, any shape: 2.5 ft between stakes minimum. Stone / cobble edging: no stakes; set-in-place in a compacted sand or concrete base. Step 4: Compute stake count. Stakes = ceiling(Total Linear Feet / Stake Spacing) + 1. The ceiling function rounds up to the next whole number. The +1 adds the terminal end stake that closes the run. Step 5: Apply soil-type warnings. Soil type does not change the stake count formula. It triggers advisory warnings about installation technique and stake product selection. Hard clay: use 10-inch steel spikes, pre-soak, rubber mallet. Soft/sandy soil: standard plastic edging pins are sufficient for poly; steel stakes are still preferred for steel edging. Rounding rules: All perimeter and total footage values are rounded to one decimal place for display. Stake counts use ceiling rounding (always round up, never down). Assumptions and Limits The 10 percent waste factor is a fixed allowance. Highly irregular freeform beds or those requiring many short-section cuts may warrant ordering an additional 5 to 10 percent beyond the calculator’s output. The circle formula assumes a perfect geometric circle. Beds that are egg-shaped, elliptical, or otherwise non-circular will return an incorrect perimeter if the Circle input is used. Use Kidney/Freeform and measure the actual path instead. The tight-curve threshold of 5 ft radius is the point at which thermal bowing in poly becomes structurally significant under typical summer temperature swings. Beds with radii between 5 and 8 feet in dark-colored poly and high sun exposure may benefit from reducing spacing to 2 to 3 feet as a precaution. The stake count calculation assumes uniform spacing for the entire run. Real installations may have corner clusters or transition zones where spacing is tighter, which will slightly increase the actual stake count needed. Stone edging is treated as a no-stake product. Some cobble border systems use landscape pins for alignment; consult the product instructions if your stone system includes a pinning specification. This tool does not account for ground slope. Steeply sloped beds may require shorter stake intervals on the downhill face to resist lateral soil pressure and edging migration. Frost heave depth requirements for steel edging vary by USDA hardiness zone and local frost depth. The 1.5-inch minimum burial recommendation in the calculator’s warning panel is a general minimum, not a zone-specific engineering specification. The 10 percent waste factor is a fixed allowance. Highly irregular freeform beds or those requiring many short-section cuts may warrant ordering an additional 5 to 10 percent beyond the calculator’s output. The circle formula assumes a perfect geometric circle. Beds that are egg-shaped, elliptical, or otherwise non-circular will return an incorrect perimeter if the Circle input is used. Use Kidney/Freeform and measure the actual path instead. The tight-curve threshold of 5 ft radius is the point at which thermal bowing in poly becomes structurally significant under typical summer temperature swings. Beds with radii between 5 and 8 feet in dark-colored poly and high sun exposure may benefit from reducing spacing to 2 to 3 feet as a precaution. The stake count calculation assumes uniform spacing for the entire run. Real installations may have corner clusters or transition zones where spacing is tighter, which will slightly increase the actual stake count needed. Stone edging is treated as a no-stake product. Some cobble border systems use landscape pins for alignment; consult the product instructions if your stone system includes a pinning specification. This tool does not account for ground slope. Steeply sloped beds may require shorter stake intervals on the downhill face to resist lateral soil pressure and edging migration. Frost heave depth requirements for steel edging vary by USDA hardiness zone and local frost depth. The 1.5-inch minimum burial recommendation in the calculator’s warning panel is a general minimum, not a zone-specific engineering specification. Critical Warnings Proper stake spacing prevents the “Sun-Warped Spaghetti” effect where heat causes poly edging to buckle. The “Sun-Warped Spaghetti” failure mode (poly edging only): Black HDPE bender board absorbs radiant heat intensely. A 100-foot run of black poly can expand by approximately 13 inches over a 100-degree Fahrenheit temperature swing. Stakes spaced at 4 to 5 feet cannot hold the bowing force at mid-span on a curved section. The result is a wavy, buckled edging line that requires complete reinstallation. This failure is preventable with 1.5-foot staking on all curves tighter than a 5-foot radius. Frost heave and shallow steel (steel edging only): Steel edging buried with less than 1.5 inches of bottom-lip depth will migrate upward during freeze-thaw cycles in cold climates. Once heaved, steel edging develops a visible lip above the soil surface that creates a tripping hazard and breaks the clean visual line of the installation. Bury deeper in zones with frost penetration below 12 inches. Joint failure on large runs: Runs over 200 linear feet require deliberate joint planning. Each section overlap should be at least 6 inches with an additional stake placed directly at the joint. Unstaked joints are the second most common failure point after thermal bowing. Hard clay and plastic stake breakage: Driving standard plastic edging pins into clay soil with a hammer instead of a rubber mallet splits the stake head and leaves the pin partially seated. A split plastic stake has approximately half the holding force of a properly seated one. Use 10-inch steel spikes in clay, and pre-soak if resistance is high. Minimum Standards Poly bender board on curves: 1.5 ft stake spacing maximum on any radius under 5 feet. Steel edging: 2.5 ft stake spacing maximum, bottom lip buried minimum 1.5 inches. Section joints: minimum 6-inch overlap, one stake at every joint regardless of the surrounding spacing interval. Stone / cobble: set into a trench 2 to 3 inches deep with compacted sand or a dry concrete base to prevent shifting. For projects where the edging abuts a hardscape structure such as a retaining wall, the edging must terminate flush with the wall face rather than overlapping it. The retaining wall calculator can help with the wall design if that structure is part of the same project. Drainage beneath curved beds is also worth considering before installation; a compacted gravel sub-base under the edging trench improves frost resistance for both steel and poly materials in wetter climates. Competitor trap: Most landscape edging calculators found online return a single linear-foot number and a generic stake count using one flat spacing interval for all materials and shapes. They treat a tight circular rose bed and a broad rectangular border identically. That flat estimate is technically correct for straight steel runs but structurally wrong for curved poly installations. An installer who follows a generic calculator’s stake count for a black poly kidney bed and skips the tight-curve spacing adjustment is setting up a failure that will be visible by mid-July. The thermal physics of HDPE under solar gain are not a matter of preference; they are the reason tight-curve staking requirements exist. Poly bender board on curves: 1.5 ft stake spacing maximum on any radius under 5 feet. Steel edging: 2.5 ft stake spacing maximum, bottom lip buried minimum 1.5 inches. Section joints: minimum 6-inch overlap, one stake at every joint regardless of the surrounding spacing interval. Stone / cobble: set into a trench 2 to 3 inches deep with compacted sand or a dry concrete base to prevent shifting. For projects where the edging abuts a hardscape structure such as a retaining wall, the edging must terminate flush with the wall face rather than overlapping it. The retaining wall calculator can help with the wall design if that structure is part of the same project. Drainage beneath curved beds is also worth considering before installation; a compacted gravel sub-base under the edging trench improves frost resistance for both steel and poly materials in wetter climates. Competitor trap: Most landscape edging calculators found online return a single linear-foot number and a generic stake count using one flat spacing interval for all materials and shapes. They treat a tight circular rose bed and a broad rectangular border identically. That flat estimate is technically correct for straight steel runs but structurally wrong for curved poly installations. An installer who follows a generic calculator’s stake count for a black poly kidney bed and skips the tight-curve spacing adjustment is setting up a failure that will be visible by mid-July. The thermal physics of HDPE under solar gain are not a matter of preference; they are the reason tight-curve staking requirements exist.

## Limitations and safety

The 10 percent waste factor is a fixed allowance. Highly irregular freeform beds or those requiring many short-section cuts may warrant ordering an additional 5 to 10 percent beyond the calculator’s output. The circle formula assumes a perfect geometric circle. Beds that are egg-shaped, elliptical, or otherwise non-circular will return an incorrect perimeter if the Circle input is used. Use Kidney/Freeform and measure the actual path instead. The tight-curve threshold of 5 ft radius is the point at which thermal bowing in poly becomes structurally significant under typical summer temperature swings. Beds with radii between 5 and 8 feet in dark-colored poly and high sun exposure may benefit from reducing spacing to 2 to 3 feet as a precaution. The stake count calculation assumes uniform spacing for the entire run. Real installations may have corner clusters or transition zones where spacing is tighter, which will slightly increase the actual stake count needed. Stone edging is treated as a no-stake product. Some cobble border systems use landscape pins for alignment; consult the product instructions if your stone system includes a pinning specification. This tool does not account for ground slope. Steeply sloped beds may require shorter stake intervals on the downhill face to resist lateral soil pressure and edging migration. Frost heave depth requirements for steel edging vary by USDA hardiness zone and local frost depth. The 1.5-inch minimum burial recommendation in the calculator’s warning panel is a general minimum, not a zone-specific engineering specification. Critical Warnings Proper stake spacing prevents the “Sun-Warped Spaghetti” effect where heat causes poly edging to buckle. The “Sun-Warped Spaghetti” failure mode (poly edging only): Black HDPE bender board absorbs radiant heat intensely. A 100-foot run of black poly can expand by approximately 13 inches over a 100-degree Fahrenheit temperature swing. Stakes spaced at 4 to 5 feet cannot hold the bowing force at mid-span on a curved section. The result is a wavy, buckled edging line that requires complete reinstallation. This failure is preventable with 1.5-foot staking on all curves tighter than a 5-foot radius. Frost heave and shallow steel (steel edging only): Steel edging buried with less than 1.5 inches of bottom-lip depth will migrate upward during freeze-thaw cycles in cold climates. Once heaved, steel edging develops a visible lip above the soil surface that creates a tripping hazard and breaks the clean visual line of the installation. Bury deeper in zones with frost penetration below 12 inches. Joint failure on large runs: Runs over 200 linear feet require deliberate joint planning. Each section overlap should be at least 6 inches with an additional stake placed directly at the joint. Unstaked joints are the second most common failure point after thermal bowing. Hard clay and plastic stake breakage: Driving standard plastic edging pins into clay soil with a hammer instead of a rubber mallet splits the stake head and leaves the pin partially seated. A split plastic stake has approximately half the holding force of a properly seated one. Use 10-inch steel spikes in clay, and pre-soak if resistance is high. Minimum Standards Poly bender board on curves: 1.5 ft stake spacing maximum on any radius under 5 feet. Steel edging: 2.5 ft stake spacing maximum, bottom lip buried minimum 1.5 inches. Section joints: minimum 6-inch overlap, one stake at every joint regardless of the surrounding spacing interval. Stone / cobble: set into a trench 2 to 3 inches deep with compacted sand or a dry concrete base to prevent shifting. For projects where the edging abuts a hardscape structure such as a retaining wall, the edging must terminate flush with the wall face rather than overlapping it. The retaining wall calculator can help with the wall design if that structure is part of the same project. Drainage beneath curved beds is also worth considering before installation; a compacted gravel sub-base under the edging trench improves frost resistance for both steel and poly materials in wetter climates. Competitor trap: Most landscape edging calculators found online return a single linear-foot number and a generic stake count using one flat spacing interval for all materials and shapes. They treat a tight circular rose bed and a broad rectangular border identically. That flat estimate is technically correct for straight steel runs but structurally wrong for curved poly installations. An installer who follows a generic calculator’s stake count for a black poly kidney bed and skips the tight-curve spacing adjustment is setting up a failure that will be visible by mid-July. The thermal physics of HDPE under solar gain are not a matter of preference; they are the reason tight-curve staking requirements exist.

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## Provenance

- Model ID: `tyg-2759`
- Model version: `1.0.0`
- Reviewed by: Umer Hayiat
- Page modified: 2026-08-20T10:20:07
- Runtime SHA-256: `2195558cbe4994616a3f899a1334736a4a165399dba363ed0d8e8e481ae3564f`

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