Garden Area
Calculator UK

The simplest way is to walk the boundary with a tape measure or a measuring wheel, recording the length and width of each section. For a basic rectangular garden, just multiply length × width. For complex shapes, divide the garden into smaller rectangles, circles, or triangles, measure each section separately, and add the areas together — which is exactly what this calculator does for you.

Square metres (m²) are the standard metric unit for area used across the UK for garden and building materials. One square metre equals approximately 10.764 square feet (ft²). The calculator shows your total in both m² and ft² so you can work with whichever unit you prefer. Most UK garden product packaging now shows coverage rates in m², making metric the most practical unit to work with.

The easiest method is to split the L-shape into two rectangles. Measure the full length and width of each rectangle, calculate each area separately (L × W), then add them together. This calculator's L-shape option does this for you automatically — you enter four dimensions (A, B, C, D) and it calculates both rectangles and returns the combined total area in m².

Measure the diameter of the circle (the full distance across the widest point). The formula is: Area = π × (diameter ÷ 2)². For example, a circular bed with a 3 metre diameter has an area of 3.14159 × 1.5² = 7.07 m². The calculator handles this automatically — you only need to enter the diameter and it does the rest.

It depends what you need the measurement for. If you want the total garden plot size (for planning or property purposes), yes — include all hard and soft landscaping. If you are calculating grass seed requirements, include only the lawn area. If you are ordering paving materials, include only the patio and path area. This calculator lets you track each zone separately with its own total, as well as giving you the grand combined figure.

Break the irregular shape down into simpler geometric shapes — rectangles, triangles, and circles. Sketch the garden on paper and draw lines to divide it into manageable sections. Measure each section and add it individually using this calculator. The running total will accumulate all sections accurately. For very complex curves, you can approximate a curved border as a series of small rectangles or use the average width multiplied by the overall length.

The average UK garden is approximately 190–200 m² in total plot area, though the actual garden space (excluding the house footprint) is considerably smaller. A typical semi-detached suburban back garden runs between 50 m² and 150 m². Terraced house gardens can be as small as 20–30 m², while detached properties may have gardens of 200 m² or more. Front gardens in the UK average around 20–40 m².

Yes — use the Rectangle or Circle shape under the "Border / Bed" zone tab to calculate the surface area of any raised bed. This gives you the m² figure you need to calculate how much compost, topsoil, or bark mulch to buy. To calculate the volume of material needed to fill a raised bed, multiply the surface area by the depth in metres (e.g. a 4 m² bed at 0.25m depth requires 1 m³ of compost).

It depends on the seed type and brand. A standard 1kg bag of ryegrass or fescue lawn seed applied at the usual rate of 35g/m² covers approximately 28 m². A 5kg bag covers around 143 m² at the same rate. For overseeding an existing lawn at 20g/m², a 1kg bag covers about 50 m². Calculate your lawn area using this tool first, then check the sowing rate on your specific seed packet to find the exact number of bags required.

To convert square metres to square yards, multiply by 1.196. For example, 50 m² × 1.196 = 59.8 yd². To convert square yards back to square metres, multiply by 0.836. The calculator displays your total in both m² and ft² automatically. Square yards are occasionally used in the UK for turf and carpet ordering — always check which unit a supplier is quoting before placing an order to avoid ordering the wrong quantity.

For most practical purposes — ordering seed, turf, or paving — use the horizontal (plan view) measurement of the garden, not the sloped surface measurement. This is the area you would see on a bird's-eye view of the garden. Measure the horizontal distance between two points rather than the distance along the slope. The only exception is if you are buying material that needs to physically cover the sloped surface (such as turf rolls laid on a bank), in which case you should add approximately 5–15% extra depending on the steepness.

A trapezoid (also called a trapezium in the UK) is a four-sided shape with one pair of parallel sides of different lengths. It is useful for calculating wedge-shaped or tapered garden areas — for example a border that is wider at one end than the other, or a path that fans out at an entrance. The formula is: Area = ½ × (Side A + Side B) × Height, where A and B are the two parallel sides and Height is the perpendicular distance between them.