Wood Fuel Heat Value Converter Forestry Tools
In-browser calculation
English
English 日本語 ລາວ Монгол Oʻzbekcha Тоҷикӣ Кыргызча Қазақша Azərbaycan Հայերեն ქართული العربية Български বাংলা čeština Dansk Deutsch Ελληνικά Español Eesti Suomi Français हिन्दी ગુજરાતી ಕನ್ನಡ मराठी മലയാളം Srpski Slovenčina Slovenščina Kiswahili Hrvatski Magyar Indonesia Italiano 한국어 Lietuvių Latviešu Nederlands Norsk Svenska Polski Português Română Русский Українська Беларуская Shqip اردو தமிழ் తెలుగు Türkçe ภาษาไทย Tiếng Việt 简体中文 繁體中文 עברית ខ្មែរ Melayu မြန်မာ ਪੰਜਾਬੀ සිංහල Tagalog नेपाली فارسی
Supports firewood and charcoal Wet basis and dry basis aware Compare kg, bag, and volume Browser only

Compare wood-fuel heat value by kg, bag, and volume

Enter a reference calorific value, moisture content, and bulk density to compare practical heat value per kg, per bag, and per occupied volume.

Use it when you need a quick comparison for firewood or charcoal sales sheets, quotes, or price explanations.

This tool uses NCV/LHV, not HHV/GCV.
All calculations stay in this browser and are not sent to a server. This result is for comparison only. Check the actual selling form and moisture basis before quoting.
Supports firewood and charcoal
Wet basis and dry basis aware
Compare kg, bag, and volume

How to use

  1. 1
    Enter the reference calorific value and choose dry basis or as received.
  2. 2
    Add moisture content to convert the value to practical heat value.
  3. 3
    Enter bulk density to calculate volume-based heat value.
  4. 4
    Enter the bag weight or bag volume to calculate per-bag heat value.
  5. 5
    Copy or share the result when you need it in a proposal or price sheet.

Quick examples

Firewood: dry basis to practical value
Input

18.8 MJ/kg, dry basis, moisture 30% dry basis, bulk density 450 kg/m3, bag 20 kg

Output

13.9 MJ/kg, 278 MJ/bag, 6.3 GJ/m3

Charcoal: bagged reference value
Input

30.8 MJ/kg, dry basis, moisture 5% dry basis, bulk density 180 kg/m3, bag 10 kg

Output

29.2 MJ/kg, 292 MJ/bag, 5.3 GJ/m3

Reference values

Dry wood and charcoal

FAO reference tables place dry wood around 18.8 MJ/kg and charcoal around 30.8 MJ/kg.

Moisture effect

Higher moisture content sharply lowers practical heat value even when the weight is the same.

Stacked volume units

A cord is 128 ft3 of stacked wood, and stere is treated as 1 m3 of stacked wood.

Glossary

Practical heat value (NCV/LHV)

Heat available for practical use after accounting for water vapor.

Moisture content (wet basis)

Water as a fraction of wet total mass.

Moisture content (dry basis)

Water as a fraction of dry mass. It can exceed 100%.

Bulk density

Mass per occupied volume, including voids.

Formulas

M_w = moisture / 100
M_d = M_w / (1 - M_w)
H_ar = H_d * (1 - M_w) - 2.44 * M_w
H_d = (H_ar + 2.44 * M_w) / (1 - M_w)
Energy_per_package = H_ar * package_mass_kg
Energy_per_m3 = H_ar * bulk_density_kg_per_m3

Frequently asked questions

Is moisture wet basis or dry basis?
Both are supported. Many sales sheets use wet basis, while biomass literature and tests often use dry basis, so the tool makes the basis explicit.
Is the heat value HHV or LHV?
This tool uses NCV/LHV as the practical heat value. If you have HHV/GCV, convert it to the same basis before using it here.
What density should I enter?
Enter the apparent density of the sold form: stacked logs, bagged charcoal, or bundled fuel including voids.
What do I need for per-bag comparison?
If the bag is sold by weight, enter the bag weight. If it is sold by volume, bulk density is required.
Can it be used outside Japan?
Yes. It is designed from English source text and can switch between metric and imperial display modes. Unit symbols stay the same; only the prose is translated.

Notes

  • Species, bark fraction, carbonization level, ash content, and storage conditions change the result.
  • Confusing dry basis and wet basis can shift the result by a large amount.
  • Bulk density changes with stacking and packing practice.
  • This tool compares heat value. It does not calculate combustion efficiency or price itself.