When to use: Enter the load mass, mounting orientation, friction, target speed, and duty cycle to get the required actuator force (with safety factor), the power needed, and a starting recommendation for electric, pneumatic, or hydraulic actuation.
This calculator computes the force a linear actuator must produce to move a given load — accounting for friction, mounting angle, and acceleration — applies a safety factor, and estimates the power required at the target speed. It also gives a starting recommendation between electric, pneumatic, and hydraulic actuation based on the resulting force and duty cycle.
For a horizontally-mounted load sliding on guides, the actuator only has to overcome friction: F = μ × m × g, where μ is the coefficient of friction between the load and its guide (typically 0.2–0.4 for linear bearings or slides, higher for plain sliding contact). For a vertically-mounted lift, the actuator must support the full weight: F = m × g. For an inclined application, both components apply: F = m × g × (sin θ + μ cos θ), where θ is the incline angle from horizontal. Any acceleration adds a dynamic force on top of the static requirement: F_accel = m × a, which matters for fast point-to-point moves more than for slow, continuous ones. The design force is the sum of static and dynamic force, multiplied by a safety factor to cover unmodeled friction, wear, and load variation.
Electric linear actuators (lead-screw or ball-screw driven) give precise, programmable position control and don't need a compressor or hydraulic power unit, making them the default choice for low-to-moderate force (roughly under 1000 lbf / 4.5 kN), low-to-moderate duty cycle applications like adjustable fixtures, valve actuation, or test equipment. Their main limitation is thermal: continuous high-force operation can overheat the drive motor, so manufacturers rate them by duty cycle.
Pneumatic cylinders are simple, fast-cycling, and effectively duty-cycle-unlimited since compressed air doesn't build up heat in the actuator the way a motor does — the trade-off is that air is compressible, so precise intermediate positioning is harder without extra sensors and control (they're naturally suited to two-position, end-to-end motion). They need a compressor and air distribution system.
Hydraulic cylinders deliver the highest force density of the three — they are the standard choice above roughly 2000 lbf / 8.9 kN, or wherever an electric or pneumatic actuator would need to be impractically large. The trade-off is a hydraulic power unit (pump, reservoir, valves), higher cost and complexity, and typically slower response than a well-sized electric actuator at lower force ranges.
The safety factor in this calculator (typically 1.3–2.0) covers friction variation over the actuator's life, minor misalignment, and load estimation error — it is not a substitute for accounting for known additional loads like seals, packing friction in a cylinder, or a spring-return force, which should be added to the load mass or static force directly before applying the safety factor. For a duty cycle above roughly 25–30%, cross-check an electric actuator's continuous-duty force rating specifically, not just its peak/intermittent rating — many manufacturers publish a significantly lower continuous force than peak force.
Enter the load mass and select the mounting orientation — horizontal (friction only), vertical (full weight), or inclined (enter the angle). Enter an estimated coefficient of friction if the load slides on guides, the target travel speed and acceleration, the duty cycle (percentage of time the actuator is actually moving), and a safety factor. The calculator returns the required design force, the estimated power, and a recommended actuator technology with the reasoning behind it — treat the recommendation as a starting point for actuator selection, not a final specification.
Linear ball or roller bearing guides typically run 0.1–0.2 (rolling friction). Plain sliding guides (bushings, dovetail slides) typically run 0.2–0.4 depending on material and lubrication. If you don't know the exact hardware yet, 0.3 is a reasonable conservative default for a guided slide; use the manufacturer's published friction coefficient once the guide is selected, since it directly scales the required force for horizontal and inclined applications.
Electric linear actuators are rated by duty cycle because their drive motor generates heat proportional to current draw over time — running near-continuously at high force can exceed the motor's thermal limit even if the instantaneous force is within its rated capacity. Pneumatic and hydraulic actuators don't have this limitation in the same way, since the working fluid (air or oil) carries heat away continuously, so they tolerate high duty cycles at rated force without a separate thermal derating curve.
For a first-pass sizing estimate, no — this calculator only models the external load. Once you've selected a specific actuator, add its rod/carriage mass to the accelerated mass and re-check the acceleration force term, especially for fast, high-acceleration moves where the actuator's own inertia can be a meaningful fraction of the total.
For a lead-screw with lead L (linear travel per screw revolution) and efficiency η (typically 0.3–0.5 for Acme threads, 0.8–0.9 for ball screws), required motor torque T = F × L / (2π × η). A higher screw efficiency needs less motor torque for the same force, but low-efficiency (low lead angle) Acme screws are often deliberately chosen because they're self-locking, similar to a worm gear — see the Gear Ratio & Torque Calculator for the general torque/efficiency relationship.
Treat the recommendation as directional, not absolute — real actuator selection also depends on precision requirements, environmental sealing (a pneumatic or hydraulic cylinder tolerates dirt/wash-down environments well; an exposed lead-screw does not), available utilities (compressed air or hydraulic power on site), noise, and cost. Near a boundary, it is worth pricing out an actuator from each viable technology rather than relying on force and duty cycle alone.
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