STN and ČSN 48 0009 – the Slovak and Czech log volume tables

Table-based scaling under the Slovak standard STN 48 0009 and the Czech ČSN 48 0009: under-bark volume from tables by mid diameter, length and species. Commonly used in the roundwood trade in Slovakia and Czechia.

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What is the STN / ČSN 48 0009?

STN 48 0009 and ČSN 48 0009 are the Slovak and Czech standards with roundwood volume tables. Under-bark volume is read by the mid-length diameter (measured over bark), the length and the species. The tables are built on the Huber formula plus species-specific bark-thickness equations, so they give less volume than plain Huber with an over-bark diameter.

Formula

V = π/4 · (d − 2k)² · L · 10⁻⁴

The tables correspond to this formula, where d is the over-bark mid diameter in cm, 2k the double bark thickness for the species (cm) and L the length in m. Measuring rules: length rounded down to whole decimetres, diameter rounded down to whole centimetres, from 20 cm the mean of two perpendicular measurements.

Worked example

A spruce log with a 30 cm mid diameter (over bark) and 4 m length scales 0.26 m³ under bark by the tables. A 30.9 cm diameter is rounded down to 30 cm, so the volume stays 0.26 m³.

Where it is used

Slovakia (STN 48 0009, measuring by STN 48 0050) and Czechia (ČSN 48 0009, Recommended Rules for Measuring and Grading Timber). Tables exist for spruce, fir, pine, beech, oak, poplar and, in Slovakia since 2017, larch.

Log volume tables ›

Frequently asked questions

How are diameter and length rounded?

The mid diameter is rounded down to whole centimetres and the length down to whole decimetres. Trim allowance is not counted in the length.

What if the log is debarked?

In Slovakia the missing bark thickness is added to the under-bark diameter and the table is used. In Czechia the volume is calculated with Huber from the under-bark diameter.

Which table applies to other species?

Maple, hornbeam, rowan, lime, cherry and fruit trees use the beech table. Elm, ash, black locust, birch and chestnut use the oak table, aspen the poplar table, Douglas fir and white pine the pine table.

Is ČSN 48 0008 the same as ČSN 48 0009?

No. ČSN 48 0009 is a volume table for logs under bark by the mid diameter measured over bark. The related standards are different: ČSN 48 0007 has tables by the mid diameter and ČSN 48 0008 volume tables for sawlogs by the top diameter. The app uses 48 0009.

Other log scaling methods

All 22 methods in the app ›

In your countryHoppus formulaA traditional British rule still used in the tropical hardwood and teak trade.m³ · GB · IE · IN · GH · MY Huber formulaThe most widely used scaling method in Central Europe: one diameter at mid-length and the length.m³ · SK · CZ · DE · AT · FR · IE Smalian formulaWhen you cannot reach the middle of the log – on a deck or a truck – you measure both ends.m³ · US · CA Doyle Log RuleThe oldest log rule still in wide use in the southern and midwestern United States.BF · US Scribner Decimal CA rule built by drawing boards into circles, today the standard for softwood logs in the western United States.BF · US · CA International ¼″ Log RuleIt allows for a ¼-inch kerf, shrinkage and log taper, so it comes closest to the real sawn timber yield.BF · US JAS (Japanese standard)The small-end diameter squared method, the standard for logs traded to Japan.m³ · JP Swedish scaling (toppmätning)Swedish sawmills pay by the small-end diameter: m³to is a cylinder from the top end.m³ · SE More methodsMid-girth, Newton, GOST 2708-75, Brereton, Vermont, Universal (Daniels), Ontario Board Foot, Ontario Cubic, Roy, Alberta, BC Firmwood, Guo Biao (GB/T 4814)All 22 methods ›