Skip to main content
Calcimator

Wood Gasifier Calculator

Design a TLUD wood gasifier stove: calculate thermal output, burn duration, fuel load, air inlet sizing, and biochar yield from reactor dimensions.

Inputs

in
in
kg/m³
kW

Results

Estimated thermal output

3.87 kW

≈ 4 microwaves

Burn duration30 min
Fuel load per batch1.33 kg
Biochar yield0.29 kg
Primary air inlet area12 cm²
Secondary air holes area6 cm²
Recommended diameter for target power13.2 cm
Reactor Volume L4.42
Power Per Cm20.02
How to Use This Calculator
  1. Enter the reactor inner diameter and fuel chamber height in cm.
  2. Set fuel bulk density and your target cooking power in kW.
  3. The calculator returns estimated thermal output, burn duration, fuel load per batch, biochar yield, and required air inlet areas.
  4. Compare estimated thermal output to your target; adjust reactor diameter if needed.
  5. Use the primary and secondary air areas to size inlet holes during construction.

How the result changes with Reactor inner diameter

Reactor inner diameterEstimated thermal output
112.08 kW
249.9 kW
4128.88 kW
5551.97 kW

What each input means

Reactor inner diameter
Inner diameter of the gasifier combustion chamber. Camp stove ≈ 10–15 cm, cookstove ≈ 15–30 cm.
Fuel chamber height
Height of the fuel loading zone. Taller = longer burn but heavier.
Fuel bulk density
Bulk density of your fuel. Wood chips ≈ 200–300, pellets ≈ 550–650, twigs ≈ 150–250 kg/m³.
Target cooking power
Desired thermal output at the pot. 1–2 kW for simmering, 3–5 kW for vigorous boiling.

What each result means

Estimated thermal output
Thermal power output at the pot from these reactor dimensions.
Burn duration
How long a full fuel load will burn before needing a refill.
Fuel load per batch
Weight of fuel that fits in the reactor chamber.
Biochar yield
Approximate biochar produced per batch (~22% of fuel mass). Can be used as soil amendment.
Primary air inlet area
Total area of bottom air holes (~7% of reactor cross-section).
Secondary air holes area
Total area of upper secondary air holes for clean combustion (~3.5% of cross-section).
Recommended diameter for target power
Reactor diameter needed to achieve your target cooking power.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Reactor inner diameter = 15, Fuel chamber height = 25, Fuel bulk density = 300, Target cooking power = 3 = 4 input(s) provided
  2. Calculate Estimated thermal output
    Estimated thermal output = (fuelConsumptionKgHr * 15 * 0.35 * 1000) / 3600
    3.87 = 3.87
  3. Calculate Burn duration
    Burn duration = fuelMassKg / fuelConsumptionKgHr
    30 = 30
  4. Calculate Fuel load per batch
    Fuel load per batch = fuelVolumeM3 * fuelDensityKgM3
    1.33 = 1.33

Related Calculators

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

Alternative Cooking

Rocket Stove Design Calculator

Calculate combustion chamber dimensions, chimney height, pot gap, and fuel consumption for a rocket stove from target BTU output.

Alternative Cooking

Biogas Stove Calculator

Calculate daily cooking hours, meals, and LPG savings from your biogas digester output and burner specifications.

Alternative Cooking

Induction Cooktop Efficiency Calculator

Compare monthly costs and energy use of induction vs. gas vs. electric resistance cooking based on your usage and energy prices.

Biomass & Bioenergy

Biochar Production Calculator

Estimate biochar yield and carbon sequestration from pyrolysis of wood, straw, or manure feedstocks.

More in Cooking, Food & Beverage.