Robot Payload Sizing Calculator
The most common robot spec mistake: sizing to part weight and forgetting the gripper. Enter part weight, EOAT weight, and safety factor — the calculator gives you the minimum rated payload and links to robots in that class.
Your inputs
the object the robot picks
vacuum cup 0.5–1.5 · parallel gripper 1–3 · magnetic 2–5
Safety factor — ISO 9283 minimum: 1.3×
Minimum rated payload
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Payload class scale
Important: rated payload ≠ peak payload
Peak payload is published at a short, specific reach. At full arm extension, rated capacity drops — sometimes by 30 to 50%. Always verify the payload-reach curve in the manufacturer's datasheet for your actual cell geometry. Spec to the next standard class up for headroom.
Sources: ISO 9283 (manipulator performance criteria), manufacturer datasheets.
Next steps
Frequently asked questions
How do I calculate the payload I need? +
Add part weight and gripper weight. Multiply by your safety factor (1.3× minimum per ISO 9283). Never spec to part weight alone — the gripper can add 1 to 5 kg, and exceeding the rated payload risks arm damage and warranty void.
What safety factor should I use? +
ISO 9283 recommends 1.3× as a minimum for fixed tooling. Use 1.5× if you plan to add a camera, sensor, or tool changer to the flange later. Use 2.0× for heavy-duty or variable-load applications where the exact EOAT weight is uncertain.
Does rated payload include the gripper weight? +
Yes. Rated payload is the total mass at the flange — part weight plus gripper plus any cables or sensors mounted on the arm. Many buyers spec to part weight only and discover the gripper exceeds the remaining capacity after the robot is ordered.
Does payload change with reach? +
Yes. Rated payload is published at a specific (usually short) reach. At full extension, the usable payload is lower, often by 30 to 50%. Always check the payload-reach curve in the manufacturer datasheet for your actual pick and place geometry.
What payload do I need for a cobot? +
The same formula applies. Add part weight plus gripper weight and multiply by 1.3. Most cobots in the Industrial Robotics Hub database handle 3 to 35 kg including tooling. If your minimum rated payload exceeds 35 kg, a fenced industrial arm is almost always the correct choice.