Moisture Meter Guide: How to Test Firewood Moisture Content Correctly

Author: Sean Summers, NFI Master Hearth Certified Technician – WoodstovePro.com

If you want hotter fires, easier starts, and less creosote, there’s one measurement that matters more than anything else: moisture content. Even “good-looking” firewood can be too wet to burn well, and wet wood is one of the biggest causes of smoky fires, poor heat output, and chimney buildup. The easiest way to take the guesswork out of wood for fireplace use is a moisture meter—an inexpensive tool that tells you whether your wood is truly seasoned wood and ready to burn.

Here’s how to test firewood moisture content the right way, plus tips for reading results and avoiding common mistakes.

What moisture content should firewood be?

For most stoves and fireplaces, seasoned wood should be at 20% moisture content or less.

• 20% or lower: burns cleaner and hotter
• Above 25%: harder to light, smokier, more creosote
• 30%+ (common with “green” wood): poor heat, heavy smoke, high buildup risk

If you’re struggling with draft, sooty glass, or weak heat, check your wood first.

What is a moisture meter (and why use one)?

A moisture meter uses small probes to measure moisture inside the wood. This matters because the outside of a log can feel dry while the inside is still wet. Testing with a meter helps you:

• Confirm wood is actually seasoned
• Compare different wood stacks or suppliers
• Burn more efficiently and reduce smoke
• Avoid wasting time on “bad wood”

It’s one of the most practical tools a wood burner can own.

How to test firewood moisture content correctly (step-by-step)

Step 1: Bring a piece of firewood to room temperature (optional but helpful)

If wood is frozen or extremely cold, readings can be slightly skewed. You can still test outdoors—just aim for consistent conditions and test multiple pieces.

Step 2: Split the log first (this is critical)

To measure real moisture content, split the log and test the freshly exposed inside face.
Do not test the bark or the outside surface—those readings are often misleading.

Step 3: Insert the probes with the grain

Press the probes firmly into the fresh split face along the grain (not across it). You want solid contact, not a shallow poke.

Step 4: Test more than one spot

Take 2–3 readings on the same split piece (center and near the edge), then test several different logs from your stack.

Step 5: Average your results

One log can be an outlier. A quick “average” from multiple pieces gives a true picture of whether your firewood is ready.

Where to test in the stack (and what to avoid)

For the most accurate results:

• Test wood from the middle of the stack (not just the top layer)
• Test a few pieces from different areas of the pile
• Avoid testing freshly rained-on exterior pieces only

Sometimes the outside dries faster than the interior—or the top dries while the middle stays damp. That’s why sampling matters.

Common mistakes homeowners make when using a moisture meter

Avoid these frequent errors:

• Testing the outside of the log instead of a fresh split face
• Testing only one piece and assuming the whole stack matches
• Using readings from bark (often inaccurate)
• Burning wood at 25–30% and calling it “seasoned”
• Storing wood fully wrapped in tarps (traps moisture and prevents drying)

If your wood tests high, it doesn’t mean you did something wrong—just that it needs more time and airflow.

What to do if your firewood is too wet

If your readings are above 20%:

• Move wood to a sunny, breezy location if possible
• Elevate the stack off the ground
• Cover only the top and leave sides open
• Split larger pieces smaller to speed drying
• Rotate older wood forward and newer wood back

If you need immediate burning wood, purchase kiln-dried or confirmed seasoned wood and test it before relying on it.

Final thoughts

A moisture meter is the simplest way to burn smarter. Testing firewood moisture content correctly—on a fresh split face and across multiple pieces—helps you confirm seasoned wood and get the best results from your stove or fireplace. Better wood means better heat, fewer issues, and a cleaner chimney.

Need help choosing accessories, storing wood, or improving your burn quality?
Contact our certified hearth professionals at 888-418-0005 or info@woodstovepro.com.