1. Select your shape
Choose from rectangle, circle, triangle, trapezoid, L-shape, annulus, or wall-and-window layouts to match your project.
What is cathedral wall square footage?
Cathedral wall square footage is the surface area of a wall with a sloped or vaulted ceiling, measured in square feet. A cathedral wall forms a right trapezoid shape. The formula is: Area = 1/2 x Width x (Height 1 + Height 2). This calculation is essential for painting, insulation, and siding on walls beneath cathedral or vaulted ceilings.
Getting started
How to Calculate Cathedral Wall Square Footage
The formula for cathedral wall area is: Area = 1/2 x Width x (Height 1 + Height 2). Width is the wall span. Height 1 is the short wall height. Height 2 is the tall wall height. A cathedral wall 14 feet wide with heights of 8 feet and 12 feet has an area of 140 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.
Basic Length Conversion
Convert other units of measure to feet with these 4 formulas:
| From | To Feet | Formula |
|---|---|---|
| Inches | Feet | Divide by 12 |
| Yards | Feet | Multiply by 3 |
| Meters | Feet | Multiply by 3.28084 |
| Centimeters | Feet | Divide by 30.48 |
For example, 48 inches ÷ 12 = 4 feet. A measurement of 5 meters × 3.28084 = 16.40 feet. The Square Foot Calculator handles these conversions automatically when you select the input unit.
Unit conversion
Area Conversion
Measure your space in inches or centimeters, calculate area in square inches or square centimeters, then convert to any unit you need, including square feet, square yards, square meters, or acres.
| Unit | Square Feet Equivalent |
|---|---|
| 1 sq ft | 144 sq in |
| 1 sq yd | 9 sq ft |
| 1 sq m | 10.764 sq ft |
| 1 acre | 43,560 sq ft |
A 300 sq ft room equals 33.33 sq yd, 27.87 sq m, or 43,200 sq in. The Square Footage Calculator displays all conversions at once so you can compare units for flooring, carpet, or tiling projects without manual math.
Shape formulas
Area Formulas for Different Shapes
The Square Foot Calculator supports 11 shape formulas for construction, interior design, landscaping, and flooring projects. Each formula below includes a diagram with labeled dimensions.
Cathedral Wall
Calculate square foot of a cathedral wall (right trapezoid)
Using measurements in feet: Area (ft²) = ½ × Width × (Height 1 + Height 2). This formula applies to a wall with a sloped top edge, typical of rooms with a cathedral ceiling. The geometric shape is a right trapezoid. A cathedral wall 14 feet (4.27 meters) wide with heights of 8 feet (2.44 meters) and 12 feet (3.66 meters) has an area of 140 sq ft.
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 square footage of a cathedral wall?
Use the formula Area = 1/2 x Width x (Height 1 + Height 2). Measure the wall width and both heights (short side and tall side) where the ceiling slopes.
What shape is a cathedral wall?
A cathedral wall is a right trapezoid - a four-sided shape with one vertical side (short wall), one sloped side (ceiling line), a horizontal top and bottom.
How much paint do I need for a cathedral wall?
Calculate the cathedral wall area, subtract windows, and divide by 350-400 sq ft per gallon. A 140 sq ft cathedral wall needs about 0.4 gallons per coat.
Can I use this for walls with vaulted ceilings?
Yes, this calculator is specifically designed for walls where the ceiling slopes from one height to another. Enter the two different wall heights and the wall width.
How do I measure cathedral ceiling height?
Measure the wall height at both ends where the ceiling meets the wall. The short height is at the low end, and the tall height is at the peak or high end.
What is the difference between cathedral and vaulted ceilings?
Cathedral ceilings follow the roof pitch symmetrically, while vaulted ceilings can have various asymmetric shapes. Both create walls with unequal heights that this calculator can measure.