Siding Square Footage Calculator

Calculate the exact square footage of siding needed. Measure each wall and subtract openings for doors and windows.

ft
ft
sq ft

Siding Square Footage Calculator Formula

Siding Area = (Height × Width × Walls) - Openings

How to Calculate Siding Square Footage

  1. 1. Measure each wall's height and width in feet
  2. 2. Multiply height by width for each wall
  3. 3. Add up all wall areas
  4. 4. Measure all door and window openings
  5. 5. Subtract openings from total wall area
  6. 6. Add 10% for waste and cuts

Example Calculation

Let's say you're calculating siding for a house with four 9ft × 50ft walls and 120 sq ft of openings.

  • wallHeight: 9
  • wallWidth: 50
  • numWalls: 4
  • openingsArea: 120

Total wall area = 1,800 sq ft, minus 120 sq ft openings = 1,680 sq ft net siding area

Tips

  • Measure each wall separately — they may have different heights or widths
  • Include gable ends in your measurements (triangular areas at roof peaks)
  • Standard door opening is about 21 sq ft (3ft × 7ft)
  • Standard window opening is about 12-15 sq ft

Frequently Asked Questions

How do you calculate square footage for siding?
Multiply each wall's height by its width, add all walls together, then subtract the area of all doors and windows. The result is your net siding square footage.
How much siding do I need for a 2,000 sq ft house?
A 2,000 sq ft single-story house typically needs about 1,600-1,800 sq ft of siding (16-18 squares), depending on the number of openings and the roof design.
Do I need to include gable ends in siding calculations?
Yes, gable ends (the triangular areas under the roof peak) need siding too. Calculate their area as 0.5 × base × height and add to your total.

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