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Vriksai Timber Intelligence

Huber FormulaMid-Section Area Volume Calculator

More accurate than Smalian for tapered logs. IS 1902:2015 India recommends Huber as the primary method for round timber measurement. Used in Germany, EU and India Forest Departments.

Why this calculation matters

Mid-diameter volume handles taper better than end-diameter methods, which matters most on the long butt logs that carry the value.

IS 1902 Primary MethodMore Accurate than SmalianGerman / EU StandardINR PricingPDF Report
HB

Huber Formula

Mid-Section Area Volume Calculator

Unit System and Species
Log Measurements
cm

Measure at exactly 50% of log length. Take two readings at 90 degrees and average.

metres
logs
cm

Total bark thickness. Auto-subtracted in UB mode.

INR/m3
cm
OK
Huber Volume Results
-
m3
Huber Volume
-
kg
Est. Weight
-
Hft
Hoppus Feet
-
INR
Value per log
IS 1902:2015 India Summary
Mid-section area-
Cubic volume-
Hoppus equiv.-
BF equivalent-
Formula Trace
About Huber Formula
Named after Johann Huber. More accurate than Smalian for logs with regular taper. IS 1902:2015 recommends this as the primary method for round timber in India. Also the standard in Germany and much of Europe. Only requires one measurement at the log midpoint. The Huber method needs just one mid-diameter reading, which makes it the fastest way to estimate log volume in the field when measuring both ends isn't practical.
Where Used?
IS 1902:2015 India (primary)Germany / EUForest Departments IndiaTimber Import YardsState Trading Corp.
Formulas
Huber: V = A_mid x L = pi x (D_mid/200)^2 x L D in cm, L in mWeight: W = V x density (kg/m3)Hoppus feet: Hft = V / 0.02832
Sources & verification
  • Huber formula (published formula)
Formula checked against the sources above by an automated regression test (tests/test-calculators.js) that derives each expected value independently of this page. Last reviewed .
FAQ
Is Huber more accurate than Smalian in India?
Yes. IS 1902:2015 recommends Huber precisely because Smalian overestimates tapered logs. Indian teak and sal logs often have 15-25% diameter reduction from butt to top, making Huber 3-8% lower than Smalian - closer to true volume.
Do I need to measure the log's middle, or can I estimate it?
Huber's whole accuracy rests on the mid-point measurement, so it's worth getting right rather than eyeballing. The formula uses the cross-section at the exact middle of the log's length and multiplies it by the length — that single mid-girth captures the log's taper better than measuring the ends. If you can't physically reach the middle of a stacked log, that's exactly when Smalian (which uses the two end diameters) becomes the more practical choice, even if it's a touch less accurate on tapered logs.
Does Huber work for logs that aren't perfectly round?
It assumes a circular cross-section, so for an oval or out-of-round log you'll get a small error. The usual fix on the ground is to take two diameter readings at the middle — the widest and the narrowest — and average them before using the formula. For badly mis-shapen or buttressed logs, no single simple formula is perfect, and large parcels are often scaled by sampling and applying a correction factor agreed between buyer and seller.
ResourcesView the formulasFormula Library
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Wood species data
Density, hardness and movement for 60 timbers
Browse all species 
How the calculation works
The area of the log at its mid-point is worked out from the mid diameter, then multiplied by the length. Using the middle rather than the two ends handles taper better, because the middle is closer to the log’s average thickness than the average of its two extremes.
Show the formula
Mid-point area Amid = pi x (Dm/200)^2 with Dm in cm under bark. Volume = Amid x length. Mass = volume x species density.
Mid-diameter handles taper better than end diameters, but on a stacked log the mid-point is often estimated rather than measured.
References and what each one provides
  • USDA Wood Handbook (FPL GTR-190)USDA Forest Products LaboratoryPublished density, moisture relationships, shrinkage coefficients and mechanical properties for a wide range of species. The reference dataset behind most wood-property figures on this site.
Unverified values are marked as such rather than presented as sourced.
Limitations of this calculation
Geometric volume from mid-point diameter assuming circular cross-section. It does not account for ovality, irregular taper, or the practical difficulty of measuring mid-diameter on a stacked log.
Do not use this for Contract scaling or sale settlement without an agreed rule and joint measurement.
Figures are engineering estimates from the inputs and assumptions shown. Verify against the actual material and, where the result affects structure or safety, against a qualified professional.
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How to use this tool
  1. Enter the log measurements below, then press Calculate.
  2. Pick your bark status from the dropdown.
  3. Fill in mid-point diameter, log length, number of logs, bark thickness. 
  4. Press Calculate. 
Worked example
With the tool's starting values — mid-point diameter = 38, log length = 4.8, number of logs = 1, bark thickness = 2.0, price per m3 = 18000 — pressing Calculate gives: 0.54438 m3 (huber volume); 299.4 kg (est. weight); 19.222 Hft (hoppus feet). 
Common mistakes to avoid