Lawn Area Calculator

Measure every lawn section, subtract obstacles, adjust slopes, estimate materials, plan watering, and calculate practical installation costs with clear, downloadable results for confident planning.

Lawn Sections

Add rectangles, circles, triangles, trapezoids, ellipses, L-shapes, or polygons.

Excluded Areas

Subtract buildings, patios, paths, pools, beds, sheds, or tree islands.

No excluded areas added.

Area Adjustment Options

%
%
degrees

Sod or Turf Estimator

Seed, Fertiliser, and Soil

kg

Irrigation Planning

Cost Estimator

%

Lawn Diagram

The preview is schematic. It helps verify section and exclusion choices.

Formula Used

Rectangle: area equals length multiplied by width. Square: area equals side squared. Circle: area equals π multiplied by radius squared.

Triangle: area equals one-half base multiplied by height. Trapezoid: average the parallel sides, then multiply by height. Ellipse: multiply π by both semi-axes.

L-shaped areas subtract the cut-out rectangle. Polygon areas use the coordinate shoelace method. Final coverage includes slope and allowance.

How to Use

  1. Add every measurable lawn section.
  2. Choose each shape and measurement unit.
  3. Enter dimensions and identical section quantities.
  4. Add patios, beds, buildings, or other deductions.
  5. Apply slope and extra purchasing allowance.
  6. Enter turf, seed, soil, irrigation, and cost details.
  7. Select the preferred result unit and calculate.
Divide irregular lawns into simple shapes. Measure each piece separately. Avoid overlapping sections or deductions.

Example Data

ExampleInputsCalculated area
Rectangular lawn12 m × 8 m96 m²
Circular lawnRadius 5 m78.54 m²
Triangular cornerBase 7 m, height 4 m14 m²
TrapezoidBases 8 m and 5 m, height 6 m39 m²
L-shaped lawn10 m × 8 m minus 3 m × 2 m74 m²
Lawn with patio100 m² gross minus 20 m² patio80 m² net
Sloped lawn100 m² at 20% slope101.98 m² surface

Frequently Asked Questions

How do I measure an irregular lawn?

Divide it into rectangles, triangles, circles, or trapezoids. Measure every section. Add their calculated areas together.

Can I subtract a patio or driveway?

Yes. Add each non-grass feature under excluded areas. The calculator subtracts them from gross area.

What allowance should I use for sod?

Five percent suits simple rectangular lawns. Ten percent handles curves and cutting. Complex layouts may require fifteen percent.

Does slope change the lawn area?

Yes. Sloped ground has more surface than its plan view. The slope adjustment estimates that additional surface.

What coordinates should polygons use?

Enter points as x,y pairs separated by semicolons. Keep every point in the same unit. Follow the boundary order.

How are sod rolls rounded?

The calculator divides final coverage by one roll’s area. It always rounds upward. This prevents material shortages.

Can this estimate overseeding?

Yes. Enter the recommended overseeding rate from the seed label. The required weight and bags update accordingly.

How is irrigation water calculated?

One millimetre over one square metre equals one litre. The calculator multiplies area, depth, and weekly cycles.

Are project costs exact quotations?

No. They are planning estimates from entered prices. Confirm labour, delivery, taxes, and supplier coverage before ordering.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.