How much heavier is green wood than kiln-dried?
Green walnut runs about 59% heavier than the same board kiln-dried — the biggest gap of the fourteen species here. What that means in pounds for an 8-foot 1x6, species by species.
Green walnut is about 59% heavier than the same board kiln-dried — the biggest gap of the fourteen species here.
An 8' 1x6 goes from 12.7 lb dry to 20.1 lb green, at 90% moisture content straight off the saw.
How that is worked out
- Below about 30% moisture content, water sits inside the wood's cell walls and the wood shrinks as it leaves. Above that point — where green lumber usually starts — the extra water just fills the empty cell cavities, adding weight without changing size.
- Walnut comes off the saw at around 90% MC, which is enough cavity water to add 59% of weight before any shrinking even starts.
- Douglas fir, by contrast, is naturally drier green — around 37% MC — so it only gains 16% on the way from the tree to the kiln.
Weight of an 8' 1x6, dry vs. green, biggest gap first
| Species | Green MC | Weight dry | Weight green | Heavier by |
|---|---|---|---|---|
| Walnut | 90% | 12.7 lb | 20.1 lb | 59% |
| Poplar | 83% | 9.7 lb | 15.1 lb | 56% |
| White pine | 73% | 8.3 lb | 12.5 lb | 49% |
| Red oak | 80% | 14.7 lb | 21.7 lb | 48% |
| Soft maple | 70% | 12.7 lb | 18.0 lb | 42% |
| Hickory | 70% | 17.0 lb | 23.3 lb | 37% |
| Cedar | 58% | 7.7 lb | 10.5 lb | 37% |
| Hard maple | 65% | 14.7 lb | 19.9 lb | 36% |
| Mahogany | 60% | 12.3 lb | 16.5 lb | 34% |
| White oak | 64% | 15.7 lb | 21.0 lb | 34% |
| Cherry | 58% | 11.7 lb | 15.5 lb | 33% |
| Sapele | 60% | 14.0 lb | 18.5 lb | 32% |
| Ash | 46% | 14.0 lb | 16.9 lb | 21% |
| Douglas fir | 37% | 11.3 lb | 13.1 lb | 16% |
Worth knowing
- Green moisture content is a typical figure for wood straight off the saw and it varies by tree, season and how long the log sat before milling — treat it as a starting point, not a measurement of the board in front of you.
- Kiln-dried figures throughout this site use about 8% moisture content, the state lumber is sold at indoors. Air-dried lumber lands around 12% — heavier than kiln-dried, lighter than green.
- This is why a truckload of green lumber costs more to move than the same load dry, and why sawmills price and ship by weight only when they have to — a green log is carrying a third or more of its weight as water that a kiln will remove for free over the following weeks.
Work out your own numbers
- Weight calculator
What a board or a stack of sheet goods weighs — for shelf brackets, a car boot, or a freight quote.
Related questions
- Why is green lumber so heavy?
- Because it is still full of water. Below about 30% moisture content wood shrinks as it dries, but above that point — which is where freshly sawn lumber usually is — the water sits in cell cavities that are already full-sized, so it adds pure weight with no size change yet. A green board can carry a third to well over half again its dry weight in water.
- Does walnut lose a lot of weight drying?
- More than any other species on this site's list — green walnut comes off the saw around 90% moisture content, and drying it to the usual 8% kiln target sheds close to 60% of its weight. It is the single biggest weight change of the fourteen species here.
- How much does wood weigh when it's freshly cut?
- It depends heavily on species — from about 16% heavier for Douglas fir to close to 60% heavier for walnut, both compared with the same board kiln-dried. There is no single rule of thumb that works across species, which is the whole reason this page is a table rather than one number.