Piling Cap Sizing Guide

What Size Piling Caps Should I Buy?

To choose the right size piling caps for your project, follow these simple guidelines:

1. Trim all pilings to their desired height before measuring

Pilings are often tapered, so measurements taken before a piling has been trimmed to the proper height can cause you to order the wrong size caps.

2. Measure the diameter at the top of each piling at its widest point

Pilings are seldom perfectly round, so measuring at the widest point ensures a proper fit.

3. Always round up

If the diameter you measure falls between two piling cap sizes, always round up to the larger size.

Dock Builders Supply Piling Cap Sizing Guide showing how to properly measure a piling for a piling cap

A Special Consideration for Square Piling Caps

When selecting square piling caps, be aware that the actual sizes of some commonly-used wooden posts are smaller than their name implies:

Post Description Actual Dimensions Cap Base Size
4 x 4 3.5" x 3.5" 3.5"
4 x 6 3.5" x 5.5" 3.5" x 5.5"
6 x 6 (Finished Cut) 5.5" x 5.5" 5.5"
6 x 6 (Rough Cut) 6.0" x 6.0" 6"