Cathedral Wall Calculator — Sloped Ceiling Area

Q: 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.

What is cathedral wall square footage?

Cathedral wall square footage equals one-half times width times the sum of two heights. Apply Area = ½ × width × (height 1 + height 2). The shape is a cathedral ceiling right trapezoid typical of vaulted rooms. For flat walls, use the wall calculator; for the trapezoid shape alone, see the trapezoid calculator.

Getting started

How to Calculate Cathedral Wall Square Footage

To calculate cathedral wall square footage, measure the wall width, the lower base height, and the peak height in feet. Apply Area = ½ × width × (height 1 + height 2). An alternative method splits the shape into a rectangle and a triangle.

1. Measure base height

Measure the wall width and lower vertical height (height 1) in feet.

2. Measure peak height

Measure from top of base wall to the peak (height 2) in feet.

3. Apply cathedral formula

Cathedral area = ½ × width × (height 1 + height 2).

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

Cathedral area times price per unit equals material cost. Apply to paint, drywall, or wood paneling on vaulted ceilings and gable walls.

There are 2 steps to calculate material cost:

Enter the cost per square foot of paint, drywall, or paneling covering the cathedral surface.
The Square Foot Calculator multiplies cathedral area by your price for material total.

Cathedral surfaces include angled cuts at the peak. Add 10-12% waste factor for siding, drywall, or paint.

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.

REFERENCES

Cathedral Wall
Calculator — Sloped Ceiling Area

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