Uneven Sides Calculator — Asymmetric Area Tool

Q: How do I find the area of a lot with 4 uneven sides?

Measure a diagonal across the lot to create two triangles. Calculate each triangle area using Heron's formula (measure all three sides of each triangle), then add the two areas together.

What is uneven sides square footage?

Uneven sides square footage equals the sum of triangular sub-areas calculated using Heron's formula. For 4-sided plots, split the shape with a diagonal into 2 triangles and calculate each area. For free-form layouts, see the irregular shape calculator.

Getting started

How to Calculate Square Footage with Uneven Sides

To calculate uneven sides square footage, measure all sides and at least one diagonal in feet. Split the shape into triangles using the diagonal. Calculate each triangle area with Heron's formula or (base × height) ÷ 2, then sum the totals.

1. Measure each side

Record the length of every side and at least one diagonal in feet.

2. Split into triangles

Draw a diagonal to split the polygon into 2 triangles.

3. Calculate and sum

Calculate each triangle area and sum for total uneven sides square footage.

Quick reference

Reference

1 acre = 43,560 square feet

1 square yard = 9 square feet

1 square meter = 10.764 square feet

1 square inch = 0.00064516 square feet

Material pricing

Calculate Cost of Materials

Uneven plot area times price per unit equals material cost. Apply the calculation to land plots, irregular gardens, and odd lot layouts.

There are 2 steps to calculate material cost:

Enter the price per square foot or per square yard of the material — sod, gravel, mulch, or paving.
The Square Foot Calculator multiplies the total uneven-sides area by your price for material total.

Uneven plots need 10-15% extra material to handle cutting and fitting along the angled edges.

FAQ

Frequently Asked Questions

How do I calculate square footage with uneven sides?

For a triangle with three known sides, use Heron's formula: s = (a+b+c)/2, then Area = sqrt[s(s-a)(s-b)(s-c)]. For four-sided areas, split into two triangles using a diagonal measurement.

How do I find the area of a lot with 4 uneven sides?

Measure a diagonal across the lot to create two triangles. Calculate each triangle area using Heron's formula (measure all three sides of each triangle), then add the two areas together.

What is Heron's formula?

Heron's formula calculates triangle area from three side lengths: First find s = (a+b+c)/2, then Area = sqrt[s(s-a)(s-b)(s-c)]. No angle measurement needed.

How many square feet is a triangle with sides 10, 12, and 14 feet?

A triangle with sides 10, 12, and 14 feet has an area of approximately 58.79 square feet. Using Heron's formula: s = 18, Area = sqrt[18 x 8 x 6 x 4] = sqrt[3456] = 58.79 sq ft.

Can I calculate a trapezoid with uneven non-parallel sides?

Yes, if you know the two parallel sides and the height between them, use: Area = [(a + b) / 2] x height. The non-parallel sides do not affect the area calculation.

How accurate is the uneven sides method?

Heron's formula gives exact results when side measurements are accurate. Measure each side carefully with a tape measure. Small measurement errors compound in the square root calculation.

REFERENCES

Uneven Sides Calculator
— Asymmetric Area Tool

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