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 NZ

This calculator works out how many fence palings you need for a paling fence, plus the rail and total timber quantities, so you know exactly what to order before you start. Getting the count wrong means an awkward extra trip to the timber yard or palings left over that you have paid for unnecessarily. You enter the total fence length, the fence height (1.2 m to 2.4 m, or a custom height), the paling width (70 mm to 150 mm broadboard, or a custom width), the gap between palings in millimetres (use a negative number for overlapping palings), the number of horizontal rails (two, three or four depending on height and exposure), and a wastage allowance for cuts and breakages. It returns the palings needed including wastage, the base paling count before wastage, the total rail length in metres, and the total paling timber in lineal metres, plus a full breakdown showing the centre-to-centre spacing and grand total timber for rails and palings combined. Standard NZ fences use 75 mm palings with a 5 mm gap, giving 80 mm centres, and a 10% wastage allowance suits a straight run, rising to 15 to 20% where there are corners, gates or angles to cut around. This gives an estimated quantity based on the dimensions entered; always check with your timber supplier and allow a few extra palings for site surprises.

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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
275
Including wastage

Base Paling Count

250

Before wastage

Total Rail Length

40.0 m

Metres of rail timber

Total Paling Timber

495.0 m

Lineal metres (incl wastage)

Paling Calculation

Fence length20.0 m

Paling width75 mm

Gap between palings5 mm

Centre-to-centre spacing80 mm

Base paling count250 palings

Wastage allowance10% (25 extra palings)

Palings to purchase275 palings

Rails and Timber

Fence height1.8 m

Number of rails2

Rail length (each run)20.0 m (x2 runs)

Total rail timber40.0 lineal metres

Paling height (each)1.8 m

Total paling timber495.0 lineal metres

Total timber (rails + palings)535.0 lineal metres

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.