Artificial Grass Calculator

Work out how much artificial grass, weed membrane, sand infill and jointing tape you need for a garden.

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How to Use This Calculator

What This Calculator Does

This artificial grass calculator works out how much fake/astro turf you need for a garden, plus the extras — weed-control membrane, kiln-dried sand infill, jointing tape and fixing pins. Artificial grass in the UK is sold off fixed-width rolls (most commonly 2 m or 4 m wide), so the calculator tells you the roll length to order and how much you'll use.

How to Use

  1. Choose metric (metres) or imperial (feet).
  2. Enter the length and width of the area you're covering.
  3. Pick your roll width — 4 m is the most common, 2 m suits narrow areas with less waste.
  4. Set a waste allowance — 10% is sensible to cover trimming, pile direction and awkward shapes.

Worked Example

For a garden 5 m long by 4 m wide using a 4 m roll:

  1. Area = 5 × 4 = 20 m².
  2. Add 10% waste = 22 m².
  3. From a 4 m wide roll you'd order about 5.5 linear metres.
  4. You'll also want around 110 kg of kiln-dried sand to brush in and weigh down the pile.

Tips

  • Lay all pieces with the pile (the direction the blades lean) running the same way, ideally facing the main viewpoint (usually the house).
  • Compact a MOT Type 1 sub-base and a layer of sharp sand before laying — use our MOT Type 1 and sand calculators for the groundwork.
  • Buy grass slightly wider than needed so you can trim to a clean edge.
  • Brush kiln-dried sand into the pile to hold the grass flat and stop it rippling in heat.

Common Questions

What width does artificial grass come in?

Most UK artificial grass is sold on 2 m and 4 m wide rolls. You buy the full roll width and a length to suit your garden, then trim to fit. The calculator uses your chosen roll width to work out the roll length to order.

How much wastage should I allow for artificial grass?

Allow around 10% for trimming, matching the pile direction and awkward shapes. For a simple rectangle you can use less; for curved or L-shaped areas allow a little more.

Do I need sand infill on artificial grass?

Kiln-dried sand infill (about 5 kg per m²) is brushed into the pile to weigh the grass down, keep the blades upright and stop it rippling in the heat. It is recommended for most installations.

What goes underneath artificial grass?

A typical build-up is a compacted MOT Type 1 sub-base, a layer of sharp or laying-course sand, then a weed-control membrane and the grass on top. This gives a firm, free-draining and weed-free base.

How do I join two pieces of artificial grass?

Butt the edges tightly together with the pile running the same way, then join them underneath with jointing tape and outdoor adhesive. Keep sand and debris off the tape while it bonds.

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