Tools: unit converter and wood weights
Calculators that use the numbers you type, a converter for the units tree work and forestry use, where diameter at breast height is measured in four countries, and the US Forest Service table of green wood weights by species.
Checked against the sources at the bottom of this page on October 6, 2026. Published tables are revised: the source has the last word.
Calculators
Each calculator is its own page. The numbers come from the person using it, and every box starts empty. Each page shows the formula in words and the sources behind the units and tables it uses.
Wood weight
Log weight estimate
Firewood
Firewood stack calculator
Plant health
Degree-day calculator
Tree measuring
Tree height calculator
Climbing
Fall factor calculator
Pricing
Margin and markup calculator
Business
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Pricing
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Credentials
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Tree aging
Tree age estimate calculator
Unit converter
A number typed in any box fills the other boxes in its group.
Length
Trunk diameter and circumference
Diameter is circumference divided by pi. Canada's National Forest Inventory describes a diameter tape as a graduated tape based on the relationship of circumference to diameter.
Force
NIST gives the kilogram-force as exactly 9.80665 newtons, from the standard acceleration of free fall.
Wood volume: cords
NIST Handbook 130 defines a cord as the amount of wood contained in a space of 128 cubic feet when the wood is ranked and well stowed.
Wood volume: board feet
NIST Handbook 130 defines a board foot as the volume of a board 1 ft long, 1 ft wide and 1 in thick, or its equivalent (144 cubic inches of wood). The USDA Forest Products Laboratory Wood Handbook glossary describes it as a board 12 in. long, 12 in. wide and 1 in. thick, or its cubic equivalent.
Weight
Density
Where diameter at breast height is measured
Diameter at breast height, written DBH or dbh, is a trunk diameter taken at a set height above the ground. Each body in the table sets its own height.
| Country | Where it is measured | Source |
|---|---|---|
| United States | 4.5 feet above the ground line on the uphill side of the tree, measured outside the bark | USDA Forest Service, Forest Inventory and Analysis field guide, version 9.3, September 2023 |
| Canada | 1.3 m above the high side of the tree, measured parallel to the tree bole, recorded to 0.1 cm | Canada's National Forest Inventory, ground sampling guidelines, version 5.0, October 2008 |
| United Kingdom | 1.3 m above ground level; on sloping ground, ground level on the upper side of the tree | Forestry Commission Booklet 49, Timber Measurement: A Field Guide, 1998 (an archive edition; the archive marks it as superseded by a later guide) |
| Australia (Victoria) | 1.3 m above ground level, over the bark | Victorian Government forests and reserves site, silviculture manual glossary |
Weight of green wood by species
The weights below are from USDA Forest Service, Northern Research Station, Research Note NRS-38, October 2009, "Specific Gravity and Other Properties of Wood and Bark for 156 Tree Species Found in North America", Table 1A.
Each figure is the average green weight of the wood, bark not included, in pounds per cubic foot as the note prints it. The kilogram figure in brackets is converted here at 1 lb/ft³ = 16.0185 kg/m³ and rounded to a whole number. The note says green weights can be extremely variable by place, season, species and part of the tree, and that the Table 1A values are rough estimates for localized areas.
The table lists 149 species from Table 1A, by common name as the note prints it.
| Species | Green weight |
|---|---|
| Ailanthus | 50 lb/ft³ (801 kg/m³) |
| Alaska yellow-cedar | 45 lb/ft³ (721 kg/m³) |
| Alligator juniper | 40 lb/ft³ (641 kg/m³) |
| American basswood | 41 lb/ft³ (657 kg/m³) |
| American beech | 54 lb/ft³ (865 kg/m³) |
| American chestnut | 55 lb/ft³ (881 kg/m³) |
| American elm | 56 lb/ft³ (897 kg/m³) |
| American holly | 57 lb/ft³ (913 kg/m³) |
| American sycamore | 52 lb/ft³ (833 kg/m³) |
| Apple spp. | 68 lb/ft³ (1089 kg/m³) |
| Atlantic white-cedar | 36 lb/ft³ (577 kg/m³) |
| Baldcypress | 51 lb/ft³ (817 kg/m³) |
| Balsam fir | 45 lb/ft³ (721 kg/m³) |
| Balsam poplar | 40 lb/ft³ (641 kg/m³) |
| Bigleaf maple | 47 lb/ft³ (753 kg/m³) |
| Bigtooth aspen | 43 lb/ft³ (689 kg/m³) |
| Bishop pine | 45 lb/ft³ (721 kg/m³) |
| Bitternut hickory | 64 lb/ft³ (1025 kg/m³) |
| Black ash | 52 lb/ft³ (833 kg/m³) |
| Black cottonwood | 46 lb/ft³ (737 kg/m³) |
| Black locust | 58 lb/ft³ (929 kg/m³) |
| Black maple | 55 lb/ft³ (881 kg/m³) |
| Black oak | 64 lb/ft³ (1025 kg/m³) |
| Black spruce | 35 lb/ft³ (561 kg/m³) |
| Black walnut | 57 lb/ft³ (913 kg/m³) |
| Black willow | 51 lb/ft³ (817 kg/m³) |
| Blackcherry | 45 lb/ft³ (721 kg/m³) |
| Blackgum | 58 lb/ft³ (929 kg/m³) |
| Blue ash | 50 lb/ft³ (801 kg/m³) |
| Boxelder | 50 lb/ft³ (801 kg/m³) |
| Bur oak | 63 lb/ft³ (1009 kg/m³) |
| Butternut | 46 lb/ft³ (737 kg/m³) |
| California black oak | 64 lb/ft³ (1025 kg/m³) |
| California red fir | 48 lb/ft³ (769 kg/m³) |
| California white oak | 63 lb/ft³ (1009 kg/m³) |
| California-laurel | 53 lb/ft³ (849 kg/m³) |
| Canyon live oak | 76 lb/ft³ (1217 kg/m³) |
| Cedar elm | 61 lb/ft³ (977 kg/m³) |
| Cherrybark oak | 64 lb/ft³ (1025 kg/m³) |
| Chestnut oak | 63 lb/ft³ (1009 kg/m³) |
| Common persimmon | 63 lb/ft³ (1009 kg/m³) |
| Cucumbertree | 49 lb/ft³ (785 kg/m³) |
| Douglas-fir | 38 lb/ft³ (609 kg/m³) |
| Eastern cottonwood | 50 lb/ft³ (801 kg/m³) |
| Eastern hemlock | 50 lb/ft³ (801 kg/m³) |
| Eastern hophornbeam | 60 lb/ft³ (961 kg/m³) |
| Eastern redcedar | 37 lb/ft³ (593 kg/m³) |
| Eastern white pine | 35 lb/ft³ (561 kg/m³) |
| Engelmann spruce | 39 lb/ft³ (625 kg/m³) |
| Flowering dogwood | 53 lb/ft³ (849 kg/m³) |
| Fremont cottonwood | 40 lb/ft³ (641 kg/m³) |
| Gambel oak | 63 lb/ft³ (1009 kg/m³) |
| Giant sequoia | 59 lb/ft³ (945 kg/m³) |
| Grand fir | 45 lb/ft³ (721 kg/m³) |
| Gray birch | 46 lb/ft³ (737 kg/m³) |
| Green ash | 52 lb/ft³ (833 kg/m³) |
| Hackberry | 50 lb/ft³ (801 kg/m³) |
| Honeylocust | 60 lb/ft³ (961 kg/m³) |
| Incense-cedar | 45 lb/ft³ (721 kg/m³) |
| Jack pine | 50 lb/ft³ (801 kg/m³) |
| Jeffrey pine | 47 lb/ft³ (753 kg/m³) |
| Kentucky coffeetree | 50 lb/ft³ (801 kg/m³) |
| Knobcone pine | 50 lb/ft³ (801 kg/m³) |
| Laurel oak | 64 lb/ft³ (1025 kg/m³) |
| Limber pine | 45 lb/ft³ (721 kg/m³) |
| Live oak | 76 lb/ft³ (1217 kg/m³) |
| Loblolly pine | 53 lb/ft³ (849 kg/m³) |
| Lodgepole pine | 39 lb/ft³ (625 kg/m³) |
| Longleaf pine | 55 lb/ft³ (881 kg/m³) |
| Mesquite spp. | 59 lb/ft³ (945 kg/m³) |
| Mockernut hickory | 65 lb/ft³ (1041 kg/m³) |
| Monterey pine | 50 lb/ft³ (801 kg/m³) |
| Mountain hemlock | 44 lb/ft³ (705 kg/m³) |
| Noble fir | 30 lb/ft³ (481 kg/m³) |
| Northern catalpa | 41 lb/ft³ (657 kg/m³) |
| Northern red oak | 64 lb/ft³ (1025 kg/m³) |
| Northern white-cedar | 36 lb/ft³ (577 kg/m³) |
| Nutmeg hickory | 62 lb/ft³ (993 kg/m³) |
| Oregon ash | 50 lb/ft³ (801 kg/m³) |
| Oregon white oak | 63 lb/ft³ (1009 kg/m³) |
| Osage-orange | 62 lb/ft³ (993 kg/m³) |
| Overcup oak | 63 lb/ft³ (1009 kg/m³) |
| Pacific dogwood | 53 lb/ft³ (849 kg/m³) |
| Pacific madrone | 60 lb/ft³ (961 kg/m³) |
| Pacific silver fir | 42 lb/ft³ (673 kg/m³) |
| Pacific yew | 55 lb/ft³ (881 kg/m³) |
| Paper birch | 52 lb/ft³ (833 kg/m³) |
| Pecan | 62 lb/ft³ (993 kg/m³) |
| Pignut hickory | 68 lb/ft³ (1089 kg/m³) |
| Pin oak | 64 lb/ft³ (1025 kg/m³) |
| Pitch pine | 50 lb/ft³ (801 kg/m³) |
| Pond pine | 51 lb/ft³ (817 kg/m³) |
| Ponderosa pine | 45 lb/ft³ (721 kg/m³) |
| Port-Orford-cedar | 42 lb/ft³ (673 kg/m³) |
| Post oak | 64 lb/ft³ (1025 kg/m³) |
| Pumpkin ash | 50 lb/ft³ (801 kg/m³) |
| Quaking aspen | 50 lb/ft³ (801 kg/m³) |
| Red alder | 46 lb/ft³ (737 kg/m³) |
| Red maple | 50 lb/ft³ (801 kg/m³) |
| Red pine | 42 lb/ft³ (673 kg/m³) |
| Red spruce | 34 lb/ft³ (545 kg/m³) |
| Redwood | 50 lb/ft³ (801 kg/m³) |
| River birch | 57 lb/ft³ (913 kg/m³) |
| Rock elm | 54 lb/ft³ (865 kg/m³) |
| Sand pine | 38 lb/ft³ (609 kg/m³) |
| Sassafras | 44 lb/ft³ (705 kg/m³) |
| Scarlet oak | 64 lb/ft³ (1025 kg/m³) |
| Serviceberry spp. | 61 lb/ft³ (977 kg/m³) |
| Shagbark hickory | 64 lb/ft³ (1025 kg/m³) |
| Shellbark hickory | 64 lb/ft³ (1025 kg/m³) |
| Shortleaf pine | 52 lb/ft³ (833 kg/m³) |
| Silver maple | 46 lb/ft³ (737 kg/m³) |
| Silverbell spp. | 44 lb/ft³ (705 kg/m³) |
| Sitka spruce | 33 lb/ft³ (529 kg/m³) |
| Slash pine | 58 lb/ft³ (929 kg/m³) |
| Slippery elm | 53 lb/ft³ (849 kg/m³) |
| Sourwood | 53 lb/ft³ (849 kg/m³) |
| Southern magnolia | 59 lb/ft³ (945 kg/m³) |
| Southern red oak | 64 lb/ft³ (1025 kg/m³) |
| Spruce pine | 45 lb/ft³ (721 kg/m³) |
| Striped maple | 47 lb/ft³ (753 kg/m³) |
| Subalpine fir | 28 lb/ft³ (449 kg/m³) |
| Sugar maple | 55 lb/ft³ (881 kg/m³) |
| Sugar pine | 49 lb/ft³ (785 kg/m³) |
| Swamp chestnut oak | 63 lb/ft³ (1009 kg/m³) |
| Swamp white oak | 63 lb/ft³ (1009 kg/m³) |
| Sweet birch | 65 lb/ft³ (1041 kg/m³) |
| Sweetbay | 49 lb/ft³ (785 kg/m³) |
| Sweetgum | 50 lb/ft³ (801 kg/m³) |
| Table Mountain pine | 54 lb/ft³ (865 kg/m³) |
| Tanoak | 65 lb/ft³ (1041 kg/m³) |
| Utah juniper | 57 lb/ft³ (913 kg/m³) |
| Virginia pine | 50 lb/ft³ (801 kg/m³) |
| Water hickory | 70 lb/ft³ (1121 kg/m³) |
| Water oak | 64 lb/ft³ (1025 kg/m³) |
| Water tupelo | 56 lb/ft³ (897 kg/m³) |
| Western hemlock | 41 lb/ft³ (657 kg/m³) |
| Western larch | 48 lb/ft³ (769 kg/m³) |
| Western redcedar | 27 lb/ft³ (432 kg/m³) |
| Western white pine | 35 lb/ft³ (561 kg/m³) |
| White ash | 50 lb/ft³ (801 kg/m³) |
| White fir | 47 lb/ft³ (753 kg/m³) |
| White oak | 63 lb/ft³ (1009 kg/m³) |
| White spruce | 35 lb/ft³ (561 kg/m³) |
| Willow oak | 64 lb/ft³ (1025 kg/m³) |
| Winged elm | 53 lb/ft³ (849 kg/m³) |
| Yellow birch | 59 lb/ft³ (945 kg/m³) |
| Yellow buckeye | 50 lb/ft³ (801 kg/m³) |
| Yellow-poplar | 49 lb/ft³ (785 kg/m³) |
Factors the converter and calculators use
The arithmetic uses the exact factors. Results show three significant figures. NIST SP 811 prints the pound as exact in its footnote, and the pound-force follows from it with the standard gravity value. NIST Handbook 130 defines the cord and the board foot.
| Unit | Equals | Basis |
|---|---|---|
| 1 inch | 2.54 cm (0.0254 m) | Exact |
| 1 foot | 0.3048 m | Exact |
| 1 pound | 0.45359237 kg | Exact |
| 1 kilogram-force | 9.80665 N | Exact |
| 1 pound-force | 4.4482216152605 N | Derived |
| 1 kilonewton | 1000 N | Defined |
| 1 cord | 128 ft³ | Defined |
| 1 board foot | 144 in³ | Defined |
| 1 cubic foot | 0.028316846592 m³ | Derived |
| 1 lb/ft³ | 16.0185 kg/m³ | Rounded |
| 1 yard | 0.9144 m | Exact |
| 1 gallon (Canadian and U.K.) | 4.54609 L | Exact |
| 1 gallon (U.S.) | 3.785412 L | Rounded |
| 1 fluid ounce (U.S.) | 29.57353 mL | Rounded |
Sources
- NIST, Guide for the Use of the International System of Units (SP 811), Appendix B.8 factors for units listed alphabetically, read October 6, 2026
- NIST, Guide for the Use of the International System of Units (SP 811), footnotes to Appendix B, read October 6, 2026
- NIST, Guide for the Use of the International System of Units (SP 811), Chapter 4 SI prefixes, read October 6, 2026
- NIST, Handbook 130, 2026 edition, Section IV.B (cord and board foot definitions), read October 6, 2026
- USDA Forest Service, Forest Products Laboratory, Wood Handbook (FPL-GTR-282), 2021, glossary entry for the board foot, read October 6, 2026
- USDA Forest Service, Forest Inventory and Analysis National Core Field Guide, version 9.3, September 2023, section 5.9.2, read October 6, 2026
- Canadian Council of Forest Ministers, Canada's National Forest Inventory ground sampling guidelines, version 5.0, October 2008, read October 6, 2026
- Forestry Commission, Timber Measurement: A Field Guide (Booklet 49), 1998, archive copy hosted by Forest Research, marked there as superseded by FCFG002, read October 6, 2026
- Victorian Government forests and reserves site, silviculture manual for Alpine Ash forests, glossary, read October 6, 2026
- USDA Forest Service, Northern Research Station, Research Note NRS-38, Miles and Smith, 2009, Table 1A, read October 6, 2026