Does this calculator account for multiple layers or courses of timbers?

No. It estimates material for a single course around the perimeter you enter. For multiple layers, multiply the timber and spike counts by the number of courses or rerun the calculator per layer.

How should I handle corners and staggered joints?

Corners and staggered joints introduce extra cuts and waste. It’s a good idea to add at least one or two extra timbers beyond the calculator’s result to give yourself flexibility when cutting and fitting.

Can I use this for curved borders?

Yes, as an approximation. Measure the curved perimeter with a tape or wheel and enter that length, but be aware that tight curves may require more, shorter pieces and therefore more timbers than a straight-run estimate suggests.

Does this replace structural engineering advice for retaining walls?

No. It only helps with basic material counts. Taller or load-bearing retaining structures may need engineered designs, drainage, tie-backs, and specific construction techniques beyond simple timber stacks.

construction calculator

Landscape Timber Calculator

Estimate timbers and spikes needed for edging or borders.

Results

Timbers needed: 8.00
Spikes needed: 16.00

How to use this calculator

Measure the total perimeter length of the area you want to edge or frame. Include all sides and curves, and convert inches to feet where needed.
Enter this perimeter length in feet into the calculator.
Enter the nominal length of the landscape timbers you plan to use (for example, 8 ft or 6 ft pieces).
Enter how many spikes or anchors you plan to use per timber (for example, 2 for short runs or 3–4 for longer, taller walls).
Review the estimated number of timbers and spikes needed for a single course (one layer) at the perimeter you specified.
If you intend to stack timbers in multiple courses, multiply the timber count by the number of layers or rerun the calculator with an adjusted perimeter.

Inputs explained

Perimeter (ft): The total run length of your landscape edging, raised bed, or border measured along the outside edge in feet. Add the lengths of all sides or approximate curves to get this number.
Timber length (ft): The length of each standard timber you plan to install (commonly 8 ft or 6 ft). Use the nominal length sold at your store and remember that cut waste and corner miters may reduce effective coverage.
Spikes per timber: The number of spikes, rebar pins, or heavy-duty landscape screws you plan to use to anchor each timber to the ground or to the course below.

How it works

We start with the total perimeter length of the border, bed, or edging run you want to build, expressed in feet.

We divide that perimeter by the length of a single timber to estimate how many full-length pieces you would need if every piece were used end-to-end.

Because you cannot buy partial timbers, we round up to the next whole timber using a ceiling function to ensure you have enough material to cover the run.

We then multiply the number of timbers by your chosen spikes-per-timber value to estimate how many spikes, rebar pins, or landscape screws you need to anchor the timbers.

The result is a simple takeoff: total timbers to purchase and total spikes or anchors required for your project.

Formula

Timbers needed = ceil(Perimeter (ft) ÷ Timber length (ft))\nSpikes needed = Timbers needed × Spikes per timber

When to use it

Estimating timbers and spikes for landscape edging around flower beds, trees, or pathways before heading to the home center.
Planning materials for simple raised beds or low landscape walls using stacked timbers.
Creating a quick takeoff for a small retaining edge or terrace where timbers provide a clean visual border.
Helping DIYers and contractors avoid multiple trips to the store by ordering enough timbers and anchoring hardware on the first visit.

Tips & cautions

Round up the timber count by at least one or two extra pieces to cover mistakes, bad cuts, and boards with defects or warping.
Increase the spikes-per-timber value for taller walls, corners, and high-traffic areas to keep timbers firmly anchored over time.
Plan staggered joints by offsetting seams between layers and buy extra material to allow for those overlaps and cuts.
Account for end cuts at corners and any decorative angles—complex layouts typically need more material than a simple perimeter suggests.
Consider drainage, gravel base, and landscape fabric as separate line items; this calculator focuses only on timbers and spikes.
Assumes a simple, single-course perimeter with straight segments; tight curves, steps, and complex shapes may require additional material.
Does not include base preparation, drainage, landscape fabric, backfill, or fasteners beyond the spikes/anchors you enter.
Does not differentiate between different timber sizes (thickness/height) or structural requirements for retaining significant soil loads.
Treats all timbers as full-length pieces; real-world projects often generate offcuts that may or may not be reusable elsewhere in the run.

Worked examples

60 ft border with 8 ft timbers

Perimeter = 60 ft, timber length = 8 ft, spikes per timber = 2.
Timbers needed = ceil(60 ÷ 8) = ceil(7.5) = 8 timbers.
Spikes needed = 8 × 2 = 16 spikes.
Interpretation: buying 8 timbers and at least 16 spikes should cover one course of a 60 ft border, plus consider one extra timber for waste.

48 ft raised bed perimeter with 6 ft timbers

Perimeter = 48 ft (for example, 12 ft × 12 ft square), timber length = 6 ft, spikes per timber = 3.
Timbers needed = ceil(48 ÷ 6) = 8 timbers.
Spikes needed = 8 × 3 = 24 spikes.
Interpretation: plan on buying at least 8 timbers and 24 spikes per course; double those numbers for a two-course raised bed.

Deep dive

Use this landscape timber calculator to estimate how many timbers and spikes you need for garden borders, edging, and simple retaining projects.

Enter total perimeter, timber length, and spikes per timber to get a quick materials list that helps you avoid under-ordering at the yard center.

Great for DIYers and pros planning flower bed borders, raised beds, and low landscape walls with standard 6 ft or 8 ft timbers.

FAQs

Does this calculator account for multiple layers or courses of timbers?: No. It estimates material for a single course around the perimeter you enter. For multiple layers, multiply the timber and spike counts by the number of courses or rerun the calculator per layer.
How should I handle corners and staggered joints?: Corners and staggered joints introduce extra cuts and waste. It’s a good idea to add at least one or two extra timbers beyond the calculator’s result to give yourself flexibility when cutting and fitting.
Can I use this for curved borders?: Yes, as an approximation. Measure the curved perimeter with a tape or wheel and enter that length, but be aware that tight curves may require more, shorter pieces and therefore more timbers than a straight-run estimate suggests.
Does this replace structural engineering advice for retaining walls?: No. It only helps with basic material counts. Taller or load-bearing retaining structures may need engineered designs, drainage, tie-backs, and specific construction techniques beyond simple timber stacks.

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This landscape timber calculator provides approximate material counts for basic edging and low landscape projects. It does not account for structural requirements, soil loads, drainage, or local building codes. Always follow manufacturer guidelines and consult local codes or a qualified professional for taller or load-bearing retaining walls.