How is "Hawaiian" wave height different from standard height?

Historically, Hawaiian wave height is measured from the back of the wave, often resulting in a measurement roughly half the size of the face height. For example, a 10-foot faces is called a 5-foot wave in Hawaii.

How do you measure a wave "face"?

Face height is the vertical distance from the trough (the bottom) of the breaking wave to the crest (the top) of the lip as it begins to break.

What is wave period and why does it matter?

Wave period is the time (in seconds) between two consecutive wave crests. A longer period (e.g., 14-18 seconds) indicates a more powerful, groundswell-driven wave compared to a shorter windswell period (e.g., 6-9 seconds).

Is a 10-foot wave dangerous for beginners?

Yes. A true 10-foot face (head-high to double-overhead) is generally considered expert-level territory, as the force of the falling water is immense and the holding time during a wipeout is significant.

Surfing & Ocean Sports

Surf Wave Height Converter

Unify the surf scales. Convert between the vertical face heights, the legendary Hawaiian scale, and metric measurements.

Face Height Entry

Vertical Wave Face (Feet)

Measure from bottom to top lip

Hawaiian Scale Entry

H-Scale

Comparison Matrix

Traditional Face Height

6.0 FT

Head High - Shoulder High

Metric Face

1.8 meters

Hawaiian Scale

3.0 FT

Defining the Surf Scales

Face Height (Standard)

The vertical measurement of the breaking wave face. This is the global standard used by the WSL (World Surf League) and forecasters to describe the physical size of the swell as it impacts the reef or shore.

Hawaiian Scale

Rooted in the 1950s, this scale measures the wave from the back. It is notoriously conservative. Many locals also use it as a way to avoid attracting tourists to dangerous or crowded breaks.

Wave Size Reference Chart

Face Height	Hawaiian	Description
1-2 FT	0-1 FT	Ankle to Knee High
3-4 FT	1-2 FT	Waist to Chest High
5-6 FT	2.5-3 FT	Head High
10-12 FT	5-6 FT	Double Overhead
20 FT+	10 FT+	Big Wave Territory