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Bark Deduction ToolOver Bark to Under Bark Converter

Calculate bark thickness and bark volume, then convert over-bark measurements to under-bark for accurate timber pricing. Species-specific bark factors for Indian, European and tropical species.

OB to UB ConversionBark Volume %IS 1902 DeductionSpecies Bark FactorsPDF Report
BK

Bark Deduction Tool

Over Bark to Under Bark Converter

Configuration
%

Auto-set by species. You can override manually.

Log Measurements - Over Bark
cm
cm
cm
metres
cm

Enter measured value to override species factor. Leave 0 to use factor.

logs
OK
Bark Deduction Results
-
cm
Bark Thickness Each Side
-
%
Bark Volume %
-
m3
Volume OB
-
m3
Volume UB
PositionOB DiameterBark Each SideUB DiameterArea OBArea UB
Calculation Steps

About Bark Deduction Tool

All log volume formulas can be calculated Over Bark (OB) or Under Bark (UB). For timber pricing, Under Bark volume is the correct basis since bark has no commercial lumber value. This tool converts OB measurements to UB using species-specific bark factors per IS 1902:2015.

Where Used?

IS 1902 IndiaLog Purchase PricingImport CustomsTimber AuctionsForest Dept India

Formulas

Bark thickness each side = OB_diameter x bark_factor / 200UB diameter = OB diameter - 2 x bark_thicknessVolume OB = pi x (D_OB_mid / 200)^2 x L (Huber method)Volume UB = pi x (D_UB_mid / 200)^2 x LBark volume % = (V_OB - V_UB) / V_OB x 100

FAQ

How does bark affect timber pricing in India?
IS 1902 specifies pricing on Under Bark volume. Buyers paying on OB measurements overpay by 8-16% (the bark volume %). Imported logs from Myanmar, Africa and Malaysia often have thick bark - always convert to UB for internal pricing.
ResourcesView the formulasFormula Library