How do I calculate how many fence palings I need?

Divide the total fence length by the spacing between paling centres (paling width plus gap). Round up to the nearest whole number. For example, a 20-metre fence with 75 mm wide palings and a 5 mm gap uses 80 mm centres, giving ceil(20,000 / 80) = 250 palings. Always add at least 10% for wastage, offcuts, and errors, giving 275 palings to purchase.

What gap should I leave between fence palings?

A 5 mm gap is standard for privacy fences using treated pine palings. This allows for timber expansion in wet weather without the palings buckling. For a more open look, a 10 to 20 mm gap is common. Overlapping palings (used on lapped-and-capped styles) have no gap and instead overlap by 10 to 20 mm, which is entered as a negative gap in this calculator.

How many rails does a fence need?

Most NZ residential fences up to 1.8 m high use two horizontal rails (top and bottom). Fences 1.8 m to 2.1 m high typically use three rails for added rigidity. Fences over 2.1 m, or those in exposed or high-wind locations, should use three or four rails. Rails are typically H4-treated 100x50 mm timber, and the total rail length equals the fence length multiplied by the number of rails.

Fence Palings Count Calculator

Work out exactly how many fence palings you need for your project. Enter the fence length, paling width, gap between palings, fence height, number of rails, and wastage allowance to get your paling count and total timber requirements.

Standard NZ paling fences use 75 mm wide treated pine palings with a 5 mm gap, giving 80 mm centre-to-centre spacing.

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Standard method Based on centre-to-centre paling spacing. Suitable for standard paling fence construction.

1. Fence Dimensions

Total fence length (metres)

Fence height (metres)

Custom height

2. Paling Details

Paling width (mm)

Custom paling width

Gap between palings (mm, use negative for overlap)

Number of horizontal rails

Wastage allowance

Your Fence Paling Count

Palings Needed
-
Including wastage

Base Paling Count

Before wastage

Total Rail Length

Metres of rail timber

Total Paling Timber

Lineal metres (incl wastage)

Paling Calculation

Fence length-

Paling width-

Gap between palings-

Centre-to-centre spacing-

Base paling count-

Wastage allowance-

Palings to purchase-

Rails and Timber

Fence height-

Number of rails-

Rail length (each run)-

Total rail timber-

Paling height (each)-

Total paling timber-

Total timber (rails + palings)-

Summary: Enter your fence dimensions above.

How to Calculate Fence Palings

The standard method for counting fence palings is to divide the fence length by the centre-to-centre spacing of each paling. The centre-to-centre spacing is simply the paling width plus the gap between palings.

Formula: Base palings = ceil(fence length (mm) / (paling width (mm) + gap (mm)))

For example, a 20-metre fence with 75 mm palings and a 5 mm gap:

Centre-to-centre spacing: 75 + 5 = 80 mm
Base palings: ceil(20,000 / 80) = 250 palings
With 10% wastage: ceil(250 x 1.10) = 275 palings to buy

Standard Paling Sizes in New Zealand

Paling Width	Common Use	Palings per 10 m (5 mm gap)
70 mm	Narrow tight-fitting fences	134
75 mm	Standard NZ paling fence	125
90 mm	Wide privacy fencing	106
100 mm	Decorative or wide-gap styles	96
150 mm	Broadboard ranch-style	65

Palings are most commonly sold in 1.8 m lengths (matching the standard fence height) or in longer lengths that are cut to size on site. Treated pine (H3 or H4 treated) is the standard choice for NZ outdoor fencing. H4 treatment is required for any timber in ground contact (posts); H3 is sufficient for palings above ground.

Rails

Horizontal rails span between posts and carry the palings. The number of rails depends on fence height:

2 rails: Fences up to 1.8 m. Top rail and bottom rail, typically set 150 to 200 mm from each end of the paling.
3 rails: Fences from 1.8 m to 2.1 m, or any fence in an exposed or high-wind location.
4 rails: Fences over 2.1 m or security fencing requiring extra rigidity.

Rails are typically 100x50 mm H4-treated timber. Total rail timber needed equals the fence length multiplied by the number of rails. Add 10% for joins, cutting, and waste.

Wastage and Overbuying

Always buy more palings than the base calculation suggests. Palings can be cracked, warped, or cut short during installation. A 10% wastage allowance is standard for a simple straight run. Allow 15% if there are corners, angles, or openings to cut around, and 20% for complex layouts with multiple gates, pillars, or angled sections.

Posts

This calculator focuses on palings and rails. Posts are typically spaced at 1.8 m to 2.4 m centres depending on the fence style and ground conditions. Number of posts = ceil(fence length / post spacing) + 1. For a 20-metre fence at 1.8 m post spacing: ceil(20 / 1.8) + 1 = 12 posts.

Worked Example

A 20-metre privacy fence, 1.8 m high, using 75 mm palings with a 5 mm gap, 2 rails, and 10% wastage:

Centre-to-centre spacing: 75 + 5 = 80 mm
Base palings: ceil(20,000 / 80) = 250
Wastage (10%): 25 extra palings
Palings to buy: 275
Total paling timber: 275 x 1.8 m = 495 lineal metres
Total rail timber: 20 m x 2 rails = 40 lineal metres
Grand total timber: 535 lineal metres

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Method: Centre-to-centre spacing method. Palings = ceil(fence length / (paling width + gap)). Wastage applied to paling count before rounding. Rail timber = fence length x number of rails. Total paling timber = palings (with wastage) x fence height.

This calculator gives an estimated quantity based on the dimensions you enter. Actual requirements may vary depending on site conditions, paling straightness, post spacing, and the specific fence style. Always check with your timber supplier and consider ordering a few extra palings to allow for any site surprises.