1. Select your shape
Choose from rectangle, circle, triangle, trapezoid, L-shape, annulus, or wall-and-window layouts to match your project.
What is sector square footage?
Sector square footage is the area of a pie-shaped slice of a circle measured in square feet. To find sector square footage, use the formula: Area = (angle/360) x pi x radius squared. Sector calculations are used for curved driveways, pie-shaped lots, and radial landscape designs.
Getting started
How to Calculate Sector Square Footage
To calculate sector square footage, measure the radius (distance from center to edge) and the central angle in degrees. The formula is: Area = (angle / 360) x pi x r squared. For a quarter-circle patio with a 10-foot radius, the area is (90/360) x 3.14159 x 100 = 78.54 square feet.
2. Enter your measurements
Input dimensions in feet, inches, yards, meters, or centimeters. The Square Foot Calculator converts units automatically.
3. Get area and cost
View results in square feet, square yards, square meters, and acres. Add a material price per unit to estimate total project cost.
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
Enter the price per square foot of material to estimate total cost. The calculator accepts pricing in square feet, square inches, square yards, or square meters and converts to the correct total based on your area.
There are 2 steps to calculate material cost:
- Enter the price per unit area. For tiling projects, enter the price per box and the number of square feet each box covers. For carpet, enter the cost per square yard. For flooring installation with hardwood or laminate, enter the cost per square foot.
- Select the unit of area that matches your pricing. The Square Foot Calculator multiplies your total area by the unit price to produce an estimated material cost, including labor costs when added to the per-unit price.
To calculate the volume of bulk materials like mulch or gravel for landscaping, convert area to cubic yards or cubic meters by multiplying the area by the depth of material.
Core formula
Basic Formula for Area
Area is the amount of space occupied by a 2-dimensional shape. The shape could be a floor, a wall, a playground, or a field. The simplest formula for area applies to any rectangular shape:
Area = Length × Width
Measure the length and width of the space in feet. Multiply the two values to get the area in square feet. A rectangular room that is 12 feet (3.66 meters) long and 10 feet (3.05 meters) wide has an area of 120 sq ft (11.15 sq m).
Square yardage is area measured in yards, and square meters is area measured in meters. Measure in feet, find the area in square feet, then convert to the unit you need.
For an L-shape room, split the floor into 2 rectangular sections, calculate each area, and add the results. Convert all measurements to the same unit before multiplying, if your dimensions are in different units like inches and feet.
Waste factor
Adding 10% Surplus for Materials
Add a 10% surplus to your calculated area to account for material waste during cutting, breakage, and pattern matching. This waste factor applies to flooring, carpet, tiling projects, and landscaping materials.
Original Area
100 sq ft
+10%
Order Amount
110 sq ft
Total Material = Area × 1.10
A room with 200 sq ft of floor area needs 220 sq ft of material: 200 × 1.10 = 220 sq ft. Increase the surplus to 15% (multiply by 1.15) for diagonal flooring installation patterns or complex tiling projects with many cuts. The Square Foot Calculator includes a waste factor field for this calculation.
FAQ
Frequently Asked Questions
How do I calculate the square footage of a sector?
Use the formula: Area = (angle/360) x pi x radius squared. Enter the radius and central angle in the Sector Square Foot Calculator for instant results in multiple units.
What is a sector in geometry?
A sector is a pie-shaped slice of a circle defined by two radii and the arc between them. The central angle determines what fraction of the full circle the sector represents.
How many square feet is a quarter-circle with a 10-foot radius?
A quarter-circle (90-degree sector) with a 10-foot radius is 78.54 square feet because (90/360) x pi x 10 squared = 78.54 sq ft.
How do I calculate a half-circle area?
A half-circle (180-degree sector) area equals pi x radius squared divided by 2. For a 12-foot diameter half-circle patio, the radius is 6 feet, so the area is 3.14159 x 36 / 2 = 56.55 sq ft.
When would I use a sector calculation?
Use sector calculations for curved patios, rounded garden beds, pie-shaped lots, and any wedge-shaped area. It is also useful for calculating material needs for curved walkways and radial landscape features.
Can I calculate a sector if I only know the arc length?
Yes, if you know the arc length and radius, calculate the angle first: angle = (arc length / radius) x (180/pi). Then use the standard sector area formula with that angle.