Estimating chipper production is essential for tree care job planning, truck logistics, and disposal cost budgeting. The volume of chips produced from a tree depends on the species, diameter, and form of the material being chipped, and the resulting chip volume is significantly greater than the solid wood volume due to the expansion that occurs when solid wood is converted to irregularly shaped chips with air spaces between them. A cord of solid wood (128 cubic feet) typically yields 2.5-3 cords of loose chips.
Production rate (tons or cubic yards per hour) determines how long the chipper needs to run on each job, how many truck loads of chips will be generated, and whether the chipper or the climber is the bottleneck in the workflow. This guide covers the factors that determine chipper throughput, the relationship between solid wood volume and chip volume, and practical methods for estimating chip production before arriving on the job site.
Chip Expansion Factors and Volume Conversion
When solid wood is chipped, the resulting pile of chips occupies a larger volume than the original solid wood because chips are irregular shapes that do not pack tightly. The ratio of chip volume to solid wood volume is called the expansion factor (or sometimes the "chip factor"), and it varies by chip size, species, and how the chips settle in the truck or pile.
Typical expansion factors range from 2.5 to 3.5, meaning one cubic yard of solid wood produces 2.5 to 3.5 cubic yards of loose chips. Smaller chips (from a chipper with sharp knives producing 1/2-inch chips) pack more densely and have a lower expansion factor. Larger chips or stringy material (from dull knives or fibrous species like elm) have a higher expansion factor because the pieces bridge across each other, creating more air space. Freshly chipped material in a chip truck typically weighs 600-1,000 pounds per cubic yard depending on species, moisture content, and how well it settles during transport.
For job planning, the key question is how many chip truck loads a given tree will produce. A typical chip truck body holds 12-15 cubic yards (loose). A large tree with an estimated 5 cubic yards of solid wood volume (roughly equivalent to 3-4 cords of firewood-size material) would produce approximately 12.5-17.5 cubic yards of chips at a 2.5-3.5 expansion factor, requiring one full chip truck load. The foliage and small branches contribute additional volume but are lighter per cubic yard than chipped trunk wood.
Chipper Throughput & Truck Capacity Calculator
Estimate chip volume from whole-tree removal by DBH or board feet. Calculates expansion factor, truck loads, and weight limits.
Chipper Throughput and Production Rates
Chipper throughput depends on machine capacity (the maximum diameter and speed of material the chipper can process), feed rate (how fast material is fed into the chipper by the ground crew), and material characteristics (straight limbs feed faster than branchy tops, and hardwoods take longer to chip than softwoods of the same diameter). Disc chippers typically process material faster than drum chippers for small-diameter material, while drum chippers handle large-diameter and irregular material more effectively.
Typical production rates for common chipper sizes: a 6-inch capacity chipper processes 2-4 cubic yards of chips per hour when fed with brush and small limbs. A 12-inch capacity chipper processes 5-15 cubic yards per hour. An 18-inch capacity chipper processes 15-30 cubic yards per hour. These rates assume continuous feeding with material appropriate for the machine size. Production drops significantly when the feed stock is branchy (requiring trimming to fit), when the ground crew is also doing other tasks (dragging brush, loading logs), or when the material is very large diameter and must be quartered to fit the feed opening.
The practical bottleneck in most tree care operations is getting material to the chipper, not the chipper's processing capacity. A well-organized ground crew with a clear drag path from the drop zone to the chipper keeps the machine running continuously. If the chipper waits between loads, the effective production rate drops proportionally. Placing the chipper as close to the work zone as traffic and site access allow minimizes drag distance and maximizes throughput.
Chipper Throughput & Truck Capacity Calculator
Estimate chip volume from whole-tree removal by DBH or board feet. Calculates expansion factor, truck loads, and weight limits.
Chip Disposal and Utilization Planning
Chip disposal is a significant cost center for tree care companies, and accurate volume estimation directly affects profitability. Options for chip disposal include: landscape mulch (the highest-value use, either sold directly or through a mulch yard), biomass fuel (delivered to a biomass power plant or industrial boiler), composting facilities (which accept green waste for a tipping fee), and landfill (the least desirable option, often with the highest tipping fee). Many municipalities and utilities accept clean wood chips for free or at low cost for use in parks, trails, and erosion control.
When bidding jobs, estimate the number of chip truck loads and factor in the disposal cost or revenue per load. If you can deliver chips to a landscape supply yard for $5-15 per cubic yard, that revenue offsets the hauling cost. If the only available disposal is a landfill charging $30-50 per ton, the disposal cost can be a significant part of the total job cost. Some tree care companies maintain their own chip yards where they stockpile, age, and color chips for retail sale, turning a disposal cost into a profit center.
Chip quality affects disposal options. Clean, uniformly sized chips from sharp chipper knives are suitable for landscape mulch and biomass fuel. Chips contaminated with soil, rocks, or foreign objects (from feeding root balls or storm debris) are only suitable for composting or landfill. Maintaining sharp chipper knives produces better quality chips, reduces fuel consumption, and increases throughput, making knife maintenance one of the highest-return maintenance activities in tree care equipment management.
Chipper Throughput & Truck Capacity Calculator
Estimate chip volume from whole-tree removal by DBH or board feet. Calculates expansion factor, truck loads, and weight limits.