GPM mainly changes speed
Higher usable flow moves a given cylinder volume faster. It does not directly multiply splitting force.
Home 3-Point Log Splitter Calculator
3-Point Log Splitter Hydraulic Calculator
Estimate theoretical cylinder force and cycle time from the hydraulic flow and pressure your tractor can supply. Optional published splitter limits let the tool distinguish “the math works” from “the documented combination is actually compatible.”
Tractor hydraulic planning tool
Enter tractor output and splitter cylinder dimensions
The example values below only demonstrate the calculation. Replace all five required inputs with values from your tractor and splitter documentation. Results update automatically.
Hydraulic compatibility status
Theoretical performance only
Enter published splitter flow/pressure limits if you want a documented-limit check.
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theoretical extension force
theoretical extension force
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theoretical retract force
theoretical retract force
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theoretical no-load cycle
theoretical no-load cycle
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cycle at entered recommended flow
cycle at entered recommended flow
Extension time: —
Return time: —
Piston area: —
Rod-side working area: —
Oil moved on extension: —
Oil moved on return: —
Flow check: —
Pressure check: —
What the calculator actually computes
Piston area = π × bore² ÷ 4.
Rod-side working area = piston area − rod area.
Theoretical extension force = pressure × piston area. The tool converts pounds-force to short tons by dividing by 2,000.
Theoretical retract force = pressure × rod-side working area.
Extension oil volume = piston area × stroke ÷ 231. Return volume uses the smaller rod-side working area.
Theoretical travel time = cylinder oil volume ÷ flow × 60. Extension + return gives the no-load theoretical hydraulic cycle.
Real machines can be slower because full tractor flow may not reach the cylinder continuously and the calculation does not model valve restriction, hose loss, pump behavior under load, detent timing, efficiency or operator delay.
Why flow and pressure cannot substitute for each other
PSI mainly changes theoretical force
Pressure acts across piston area. A pressure number without cylinder bore does not establish tons.
Cylinder size links both
A larger bore increases theoretical force but also increases the oil volume that must move, which can lengthen cycle time at the same GPM.
Documentation still wins
Couplers, hoses, open/closed-center requirements and the splitter's allowable pressure can make a mathematically plausible setup incompatible.
Current Boss 3PT16T21 example: why exact source verification matters
The current normalized Boss Industrial 3PT16T21 record publishes a 3.5-inch cylinder bore and a 2,000–3,700 PSI tractor pressure range. But the current exact manufacturer page is internally inconsistent on two important fields: its title/specification table say 16 tons while body text says maximum potential is 13 tons, and body text says 4 GPM minimum while the specification table recommends 5–10 GPM.
For that reason, this calculator does not preload the Boss model as if those values were settled. Enter the exact values you decide are authoritative after checking the current product page/manual. The model remains available on the 3-Point Log Splitters guide with the discrepancy stated openly.
Use the calculator as a compatibility planning step
Do not raise relief pressure, alter tractor hydraulics or exceed a splitter's published pressure range to chase a force number. If the exact hydraulic-system type, couplers or pressure limit are unclear, confirm them in the tractor and splitter manuals before connecting the machines.
Frequently asked questions
How do I estimate log splitter force from tractor hydraulic pressure?
The calculator multiplies hydraulic pressure by piston area to estimate theoretical extension force. The result is theoretical cylinder force, not a guarantee of the splitter manufacturer's advertised tonnage.
Does more tractor GPM create more splitting force?
No. Flow mainly changes how quickly the cylinder can move. Pressure and cylinder area are the primary theoretical force inputs.
Why is the calculated cycle time only theoretical?
It assumes the entered flow reaches the cylinder continuously and does not model valve losses, hose restrictions, pump behavior under load, detents, operator delay or system inefficiency.
What if my tractor pressure is above the splitter's published maximum?
Do not connect or operate the combination until the exact tractor and splitter documentation confirms compatibility. The calculator does not recommend changing relief pressure or modifying hydraulics.