!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> Equilibrium Moisture Content

The moisture content of wood is directly related to the humidity and temperature of the surrounding air.  The equilibrium moisture content (EMC) occurs when the wood has reached an equilibrium with its environment and is no longer gaining or losing moisture. Here is a table for looking up the EMC of wood, given the temperature and relative humidity:
Relative Humidity % Ambient Air Temperature - degrees Fahrenheit
0 30 40 50 60 70 80 90 100 110 120 130
5 1.4 1.4 1.4 1.3 1.3 1.3 1.2 1.2 1.1 1.1 1.0
10 2.6 2.6 2.6 2.5 2.5 2.4 2.3 2.3 2.2 2.1 2.0
15 3.7 3.7 3.6 3.6 3.5 3.5 3.4 3.3 3.2 3.0 2.9
20 4.6 4.6 4.6 4.6 4.5 4.4 4.3 4.2 3.0 3.9 3.7
25 5.5 5.5 5.5 5.4 5.4 5.3 5.1 5.0 4.9 4.7 4.5
30 6.3 6.3 6.3 6.2 6.2 6.1 5.9 5.8 5.6 5.4 5.2
35 7.1 7.1 7.1 7.0 6.9 6.8 6.7 6.5 6.3 6.1 5.9
40 7.9 7.9 7.9 7.8 7.7 7.6 7.4 7.2 7.0 6.8 6.6
45 8.7 8.7 8.7 8.6 8.5 8.3 8.1 7.9 7.7 7.5 7.2
50 9.5 9.5 9.5 9.4 9.2 9.1 8.9 8.7 8.4 8.2 7.9
55 10.4 10.4 10.3 10.2 10.1 9.9 9.7 9.5 9.2 8.9 8.7
60 11.3 11.3 11.2 11.1 11.0 10.8 10.5 10.3 10.0 9.7 9.4
65 12.4 12.3 12.3 12.1 12.0 11.7 11.5 11.2 11.0 10.6 10.3
70 13.5 13.5 13.4 13.3 13.1 12.9 12.6 12.3 12.0 11.7 11.3
75 14.9 14.9 14.8 14.6 14.4 14.2 13.9 13.6 13.2 12.9 12.5
80 16.5 16.5 16.4 16.2 16.0 15.7 15.4 15.1 14.7 14.4 14.0
85 18.5 18.5 18.4 18.2 17.9 17.7 17.3 17.0 16.6 16.2 15.8
90 21.0 21.0 20.9 20.7 20.5 20.2 19.8 19.5 19.1 18.6 18.2
95 24.3 24.3 24.3 24.1 23.9 23.6 23.3 22.9 22.4 22.0 21.5
98 26.9 26.9 26.9 26.8 26.6 26.3 26.0 25.6 25.2 24.7 24.2