This calculator uses Smalian's formula to estimate the volume of multiple logs in cubic metres (m³) and also converts each result to cubic feet (ft³).
Click Add Log to enter multiple logs. Input the length and the two diameters of each log. Click "Calculate" to view the board feet per log and the total. Use "Copy History" to save your results.
Prefer imperial measurements? Try the Smalian's Formula - Multi-Log Calculator - Imperial.
More useful forestry calculators:
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Total Volume : 0 m³ / 0 ft³
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Accurate diameter and length measurements ensure reliable volumes for inventory, transportation planning, and sales calculations.
Smalian's formula (metric) for a single log's volume is given by:
\[ V \;=\; \frac{\pi}{80000} \,\bigl(D_{s}^{2} + D_{l}^{2}\bigr)\,L \]
where:
This formula yields volume \(V\) in cubic metres (m³).
Suppose we have a single log with these measurements:
Compute step by step:
Step 1: Square the diameters (in cm):
\(D_{s}^{2} = 30^{2} = 900,\quad D_{l}^{2} = 35^{2} = 1225.\)
Step 2: Sum the squared diameters:
\(D_{s}^{2} + D_{l}^{2} = 900 + 1225 = 2125.\)
Step 3: Multiply by length \(L = 2.50\) m:
\(\bigl(D_{s}^{2} + D_{l}^{2}\bigr)\,L = 2125 \times 2.50 = 5312.5.\)
Step 4: Multiply by \(\pi/80000\):
\[ V = \frac{\pi}{80000} \times 5312.5 = \pi \times \frac{5312.5}{80000} = \pi \times 0.06640625 \approx 0.2087 \]
Numerically, \(0.06640625 \times \pi \approx 0.2087.\)
Step 5: Final volume (rounded to three decimals):
\[ V \approx 0.209 \;\text{m³}. \]
To convert this result to cubic feet (ft³), multiply by 35.3147:
\[ V_{\text{ft?}} = 0.2087 \times 35.3147 \approx 7.37 \;\text{ft³}. \]
Summary of sample result: