Waxing vs Waning: The Easiest Way to Remember

Waxing and waning are the two words people trip over with the moon. They are actually simple. One means the moon is growing, the other means it is shrinking. Here is how to keep them straight for good.

The plain meaning

• Waxing means the lit part is growing, heading toward a full moon. Think of candle wax building up.
• Waning means the lit part is shrinking, heading toward a new moon. Think of something fading or winding down.

That is the whole idea. Growing or shrinking. Everything else is just naming the stages in between.

The glance trick (Northern Hemisphere)

You can often tell which one you are looking at without any tools:

• If the right side of the moon is lit, it is usually waxing (growing).
• If the left side is lit, it is usually waning (shrinking).

A memory aid: light on the right, the moon is getting bright. In the Southern Hemisphere, flip the sides.

The stages in order

Waxing goes: new, brightening crescent, half full, almost full, full. Waning goes: full, just past full, half empty, fading crescent, back to new. The full cycle takes about 29.5 days.

Or just check

If you would rather not guess, moontrack shows tonight's phase, whether it is waxing or waning, and how lit it is right now.

Want the full breakdown? Read the 8 moon phases explained.