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Total timber
Adds the vertical timber to the plates and then applies the waste allowance. The result is the linear metres of timber to buy.
The Formula
T = (n h + P) (1 + w)
Adds the vertical timber to the plates and then applies the waste allowance. The result is the linear metres of timber to buy.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| n | Stud count | studs | Including studs added for openings. |
| h | Stud length | metres | Wall height less the plate thicknesses. |
| P | Plate length | metres | Three runs along the wall. |
| w | Waste allowance | dimensionless | A decimal, so ten percent is 0.1. |
| T | Total timber | metres | Linear metres to order. |
What Each Symbol Means
nstuds
Stud count
Including studs added for openings.
hmetres
Stud length
Wall height less the plate thicknesses.
Pmetres
Plate length
Three runs along the wall.
wdimensionless
Waste allowance
A decimal, so ten percent is 0.1.
Tmetres
Total timber
Linear metres to order.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate lumber for framing page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Lumber For Framing, filed under Everyday Life. Every number the guide produces comes from substituting into this one line.