1. Identify polygon type
Regular polygon (all sides equal) or irregular polygon (uneven sides).
What is polygon square footage?
Polygon square footage equals one-half times perimeter times apothem for regular polygons. For irregular polygons, divide the shape into triangles and rectangles, then sum the area of each section. See the irregular shape calculator for free-form lot layouts.
Getting started
How to Calculate Polygon Square Footage
To calculate polygon square footage, identify the polygon type. For regular polygons, measure one side and the apothem (center to edge midpoint). For irregular polygons, split the shape into triangles and rectangles, then sum each area.
2. Apply formula or split
Regular polygon area = ½ × perimeter × apothem. Irregular: split into triangles/rectangles.
3. Sum the parts
For irregular polygons, calculate each sub-shape and add the areas together.
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
Polygon area times price per unit equals material cost. Apply polygon square footage to hexagonal patios, gazebos, and decorative gardens.
There are 2 steps to calculate material cost:
- Enter the price per square foot of pavers, concrete, sod, or other material covering the polygon.
- The Square Foot Calculator multiplies polygon area by the unit price for material total.
Polygons have multiple edges and cuts. Add 12-15% extra material for trimming and corner fitting.
FAQ
Frequently Asked Questions
How do I calculate the square footage of a polygon?
Break the polygon into rectangles and triangles, calculate each area separately, and add them together. For regular polygons, use Area = (perimeter x apothem) / 2.
What is the easiest way to measure an irregular polygon?
Divide the shape into rectangular and triangular sections using straight lines. Measure each section independently, calculate their areas, and sum the totals.
How do I calculate the area of a hexagonal patio?
A regular hexagon area = (3 x sqrt(3) / 2) x side squared. For a hexagon with 6-foot sides, the area is approximately 93.53 square feet.
How many square feet is a pentagon with 8-foot sides?
A regular pentagon with 8-foot sides has an area of approximately 110.11 square feet. Use the formula: Area = (perimeter x apothem) / 2, where apothem = side / (2 x tan(pi/5)).
Can I use this calculator for an octagonal room?
Yes, break the octagon into rectangles and triangles, or use the regular polygon formula. A regular octagon with 5-foot sides has an area of approximately 120.71 square feet.
What is an apothem?
An apothem is the perpendicular distance from the center of a regular polygon to the midpoint of any side. It is used in the formula Area = (perimeter x apothem) / 2 to calculate polygon area.
REFERENCES
Further Reading & References
Trusted external sources and related sections on this site. External links open authoritative references on Wikipedia and government agencies.
Explore this Square Foot Calculator site
Authoritative external references
- WIKIPolygon — Wikipedia
- WIKIRegular polygon — Wikipedia
- WIKIArea — Wikipedia