Tree Weight Calculator for Construction

Enter Measurements

Choose a trunk model, add allowances, then calculate an estimated weight and lift design load.

Measurement system

Base diameter uses cm or inches, depending on system.

Shape model

Frustum is best for tapered trunks and logs.

Number of stems

Use 2+ if estimating multi-stem trees.

Base diameter (cm or in)

Enter a positive base diameter.

Top diameter (cm or in)

Required for frustum; ignored for others.

Height (m or ft)

Enter a positive height.

Wood density preset

Preset fills density using common oven-dry values.

Wood density (kg/m³)

If unsure, start between 450–750 kg/m³.

Enter a positive density.

Moisture content (%)

Higher moisture increases weight substantially.

Bark allowance (%)

Adds volume for thick bark and irregularity.

Branches / crown allowance (%)

Use 0% for a clean log; 10–30% for crown.

Safety factor

Multiplies total green mass to size lift loads.

Reset

Formula Used

Unit conversion: cm → m (÷100), in → m (×0.0254), ft → m (×0.3048).
Cylinder volume: V = π × (D/2)² × H
Cone volume: V = (π × (D/2)² × H) / 3
Frustum volume: V = (π × H / 12) × (D₁² + D₁D₂ + D₂²)
Adjusted volume: V_adj = V × (1 + Bark%/100)
Dry mass: M_dry = V_adj × Density
Green mass: M_green = M_dry × (1 + Moisture%/100)
Total green mass: M_total = M_green × (1 + Branch%/100)
Lift design load: L = M_total × Safety factor

How to Use This Calculator

Select a measurement system that matches your tape and rangefinder.
Choose a trunk model. Use Frustum when you can measure top diameter.
Enter base diameter, height, and a realistic wood density value.
Add moisture, bark, and crown allowances based on tree condition.
Set a safety factor for lifts, then click Calculate Weight.
Use Download CSV or Download PDF to share results.

Tip: If only one diameter is known, choose Cylinder or Cone for a conservative estimate.

Example Data Table

Scenario	System	Model	Base D	Top D	Height	Density	Moisture	Total Green Mass	Lift Load (SF)
Urban removal	Metric	Frustum	55 cm	35 cm	8 m	720 kg/m³	40%	~ 1,170 kg	~ 1,460 kg (1.25)
Clean log	Metric	Cylinder	40 cm	—	6 m	500 kg/m³	25%	~ 470 kg	~ 590 kg (1.25)
Large lift plan	Imperial	Frustum	26 in	18 in	22 ft	750 kg/m³	55%	~ 2,270 kg	~ 3,060 kg (1.35)

Examples are illustrative. Site conditions and decay can change actual weight.

Professional Notes for Construction Planning

On constrained sites, a tree’s estimated weight supports method statements, pick sequencing, and transport planning. Record units, measurement method, and assumptions so the same inputs can be reviewed during permit checks, toolbox talks, and lifting approvals. This supports consistent sign-off across teams.

Why Tree Weight Matters on Site

Tree removal near structures often becomes a lifting and logistics problem, not just a cutting task. Knowing an estimated green mass helps you select an access route, choose a crane class, and verify that mats, outriggers, and exclusion zones match the expected load path.

Inputs That Drive the Estimate

This calculator uses trunk geometry (cylinder, frustum, or segmented), height, and average diameter to estimate trunk volume. It then multiplies volume by wood density to obtain trunk mass, and optionally adds branch and foliage percentage to represent the crown.

Density, Moisture, and Species Differences

Wood density is the biggest variable. Freshly cut “green” timber carries free water, so the same trunk can weigh far more than a seasoned log. If you do not know the species, start with a conservative mid-range density and increase it when the tree appears wet, heavy, or resinous.

Benchmarks, Limits, and Safe Working Use

For rough planning, many softwoods fall around 350–550 kg/m³ green, while many hardwoods fall around 550–900 kg/m³ green. A 40 cm diameter trunk that is 6 m long can exceed 400 kg before crown and rigging effects. Real trees are not perfect solids: hollows, taper changes, heavy limbs, and uneven moisture introduce error. Treat the output as an estimate, apply an appropriate safety factor, and consider dynamic effects (sling angles, swing, wind, shock loading). The displayed kN value uses 9.81 m/s² and helps compare against rated capacities. Where required, follow the project lifting plan and verify final loads with qualified personnel.

FAQs

Q1. What tree parts does the estimate include?

The trunk mass is calculated from geometry and density. The crown is added as a percentage to account for branches and foliage. Set crown percentage to 0% for a clean log section.

Q2. Which trunk model should I choose?

Use Cylinder for uniform logs, Frustum when you can measure top diameter, and Segmented for irregular stems. Segmented usually gives the most realistic result when you have multiple diameter points.

Q3. How do I pick a wood density value?

If species is known, use published green density. If unknown, start around 500 kg/m³, then adjust higher for dense hardwoods or very wet timber, and lower for light softwoods.

Q4. Does the calculator account for hollows or rot?

No. Hollows, decay, or cavities reduce real mass, but external water and heavy limbs can increase it. If the tree condition is uncertain, treat results as planning guidance and keep a conservative safety factor.

Q5. Why is a safety factor included?

Lifting and rigging involve dynamic effects such as swing, shock, and sling angles. Multiplying by a safety factor helps you size picks and set conservative working loads for planning purposes.

Q6. Can I export results for my method statement?

Yes. After calculating, you can download a CSV for spreadsheets and a PDF summary for documentation. The exports capture inputs, calculated volumes, and both total and safety-factor loads.

Q7. What units should I use on site?

Select Metric for centimeters and meters, or Imperial for inches and feet. The results show kilograms and pounds, plus kN estimates. Keep your field measurements consistent with the selected system.

Good practice: Keep a margin for rigging, sling angles, wind, and pick dynamics. Confirm final loads with a qualified lifting plan when required.