Lumber Expansion/Contraction Calculator
 
 
Select lumber species:
How was the lumber sawn?:
 
Lumber width (inches):
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Lumber width (cm):
 
Starting moisture content (%):
Final moisture content (%):
 
 
Fill in blanks above. Use either inches or cm.
 
 
1Equilibrium moisture content of wood, exposed to outdoor atmosphere, in different US states at various months:
State
City
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
AK
Juneau
16.5
16.0
15.1
13.9
13.6
13.9
15.1
16.5
18.1
18.0
17.7
18.1
AL
Mobile
13.8
13.1
13.3
13.3
13.4
13.3
14.2
14.4
13.9
13.0
13.7
14.0
AZ
Flagstaff
11.8
11.4
10.8
9.3
8.8
7.5
9.7
11.1
10.3
10.1
10.8
11.8
AZ
Phoenix
9.4
8.4
7.9
6.1
5.1
4.6
6.2
6.9
6.9
7.0
8.2
9.5
AR
Little Rock
13.8
13.2
12.8
13.1
13.7
13.1
13.3
13.5
13.9
13.1
13.5
13.9
CA
Fresno
16.4
14.1
12.6
10.6
9.1
8.2
7.8
8.4
9.2
10.3
13.4
16.6
CA
Los Angeles
12.2
13.0
13.8
13.8
14.4
14.8
15.0
15.1
14.5
13.8
12.4
12.1
CO
Denver
10.7
10.5
10.2
9.6
10.2
9.6
9.4
9.6
9.5
9.5
11.0
11.0
DC
Washington
11.8
11.5
11.3
11.1
11.6
11.7
11.7
12.3
12.6
12.5
12.2
12.2
FL
Miami
13.5
13.1
12.8
12.3
12.7
14.0
13.7
14.1
14.5
13.5
13.9
13.4
GA
Atlanta
13.3
12.3
12.0
11.8
12.5
13.0
13.8
14.2
13.9
13.0
12.9
13.2
HI
Honolulu
13.3
12.8
11.9
11.3
10.8
10.6
10.6
10.7
10.8
11.3
12.1
12.9
ID
Boise
15.2
13.5
11.1
10.0
9.7
9.0
7.3
7.3
8.4
10.0
13.3
15.2
IL
Chicago
14.2
13.7
13.4
12.5
12.2
12.4
12.8
13.3
13.3
12.9
14.0
14.9
IN
Indianapolis
15.1
14.6
13.8
12.8
13.0
12.8
13.9
14.5
14.2
13.7
14.8
15.7
IA
Des Moines
14.0
13.9
13.3
12.6
12.4
12.6
13.1
13.4
13.7
12.7
13.9
14.9
KS
Wichita
13.8
13.4
12.4
12.4
13.2
12.5
11.5
11.8
12.6
12.4
13.2
13.9
KY
Louisville
13.7
13.3
12.6
12.0
12.8
13.0
13.3
13.7
14.1
13.3
13.5
13.9
LA
New Orleans
14.9
14.3
14.0
14.2
14.1
14.6
15.2
15.3
14.8
14.0
14.2
15.0
ME
Portland
13.1
12.7
12.7
12.1
12.6
13.0
13.0
13.4
13.9
13.8
14.0
13.5
MA
Boston
11.8
11.6
11.9
11.7
12.2
12.1
11.9
12.5
13.1
12.8
12.6
12.2
MI
Detroit
14.7
14.1
13.5
12.6
12.3
12.3
12.6
13.3
13.7
13.5
14.4
15.1
MN
Minneapolis–St.Paul
13.7
13.6
13.3
12.0
11.9
12.3
12.5
13.2
13.8
13.3
14.3
14.6
MS
Jackson
15.1
14.4
13.7
13.8
14.1
13.9
14.6
14.6
14.6
14.1
14.3
14.9
MO
St. Louis
14.5
14.1
13.2
12.4
12.8
12.6
12.9
13.3
13.7
13.1
14.0
14.9
MT
Missoula
16.7
15.1
12.8
11.4
11.6
11.7
10.1
9.8
11.3
12.9
16.2
17.6
NE
Omaha
14.0
13.8
13.0
12.1
12.6
12.9
13.3
13.8
14.0
13.0
13.9
14.8
NV
Las Vegas
8.5
7.7
7.0
5.5
5.0
4.0
4.5
5.2
5.3
5.9
7.2
8.4
NV
Reno
12.3
10.7
9.7
8.8
8.8
8.2
7.7
7.9
8.4
9.4
10.9
12.3
NM
Albuquerque
10.4
9.3
8.0
6.9
6.8
6.4
8.0
8.9
8.7
8.6
9.6
10.7
NY
New York
12.2
11.9
11.5
11.0
11.5
11.8
11.8
12.4
12.6
12.3
12.5
12.3
NC
Raleigh
12.8
12.1
12.2
11.7
13.1
13.4
13.8
14.5
14.5
13.7
12.9
12.8
ND
Fargo
14.2
14.6
15.2
12.9
11.9
12.9
13.2
13.2
13.7
13.5
15.2
15.2
OH
Cleveland
14.6
14.2
13.7
12.6
12.7
12.7
12.8
13.7
13.8
13.3
13.8
14.6
OK
Oklahoma City
13.2
12.9
12.2
12.1
13.4
13.1
11.7
11.8
12.9
12.3
12.8
13.2
OR
Pendleton
15.8
14.0
11.6
10.6
9.9
9.1
7.4
7.7
8.8
11.0
14.6
16.5
OR
Portland
16.5
15.3
14.2
13.5
13.1
12.4
11.7
11.9
12.6
15.0
16.8
17.4
PA
Philadelphia
12.6
11.9
11.7
11.2
11.8
11.9
12.1
12.4
13.0
13.0
12.7
12.7
SC
Charleston
13.3
12.6
12.5
12.4
12.8
13.5
14.1
14.6
14.5
13.7
13.2
13.2
SD
Sioux Falls
14.2
14.6
14.2
12.9
12.6
12.8
12.6
13.3
13.6
13.0
14.6
15.3
TN
Memphis
13.8
13.1
12.4
12.2
12.7
12.8
13.0
13.1
13.2
12.5
12.9
13.6
TX
Dallas–Ft.Worth
13.6
13.1
12.9
13.2
13.9
13.0
11.6
11.7
12.9
12.8
13.1
13.5
TX
El Paso
9.6
8.2
7.0
5.8
6.1
6.3
8.3
9.1
9.3
8.8
9.0
9.8
UT
Salt Lake City
14.6
13.2
11.1
10.0
9.4
8.2
7.1
7.4
8.5
10.3
12.8
14.9
VA
Richmond
13.2
12.5
12.0
11.3
12.1
12.4
13.0
13.7
13.8
13.5
12.8
13.0
WA
Seattle–Tacoma
15.6
14.6
15.4
13.7
13.0
12.7
12.2
12.5
13.5
15.3
16.3
16.5
WI
Madison
14.5
14.3
14.1
12.8
12.5
12.8
13.4
14.4
14.9
14.1
15.2
15.7
WV
Charleston
13.7
13.0
12.1
11.4
12.5
13.3
14.1
14.3
14.0
13.6
13.0
13.5
WY
Cheyenne
10.2
10.4
10.7
10.4
10.8
10.5
9.9
9.9
9.7
9.7
10.6
10.6
 
  If you are unsure of what your starting and final moisture content will be (dependent on location), you can use a difference of 10% for a worst-case-scenario. i.e. 4% --> 14%  
     
 
References:
 
  (1) Forest Products Laboratory. 1999. Wood handbook—Wood as an engineering material.U.S. Department of Agriculture, Forest Service, Forest Products Laboratory.  
 
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