Pergola Calculator

The golden ratio (1.618:1) creates naturally pleasing proportions. For pergolas, this means if your pergola is 16 feet long, the ideal width would be about 10 feet (16 ÷ 1.618), creating a visually balanced structure.

Posts should typically be buried 2-3 feet deep, or about 1/3 of the above-ground height. For an 8-foot tall pergola, bury posts 2.5-3 feet deep for proper stability and wind resistance.

6x6 posts provide significantly more strength and stability than 4x4 posts. Use 4x4 posts only for smaller pergolas (under 10x10 feet), while 6x6 posts are recommended for larger structures and areas with high winds.

Rafters are typically spaced 16 or 24 inches on center. Use 16-inch spacing for heavier loads or more shade coverage, and 24-inch spacing for lighter structures or when you want more sunlight to filter through.

Permit requirements vary by location and pergola size. Generally, pergolas under 200 square feet and less than 12 feet tall may not require permits, but always check with your local building department before starting construction.

Cedar and redwood are naturally rot-resistant and ideal for outdoor use. Pressure-treated pine is more budget-friendly and also suitable. Avoid untreated lumber as it will deteriorate quickly in outdoor conditions.

Beam size depends on span length and load requirements. For spans up to 10 feet, 2x8 beams work well. For 10-14 feet, use 2x10 beams, and for spans over 14 feet, consider 2x12 beams or engineered lumber.

Attached pergolas can save materials and create seamless outdoor living spaces. However, ensure proper flashing and structural attachment to prevent water damage and meet local building codes for attached structures.