Can a load under rated payload still overload the wrist?

Yes. Rated payload holds only inside the maker's load diagram. A long gripper or offset part can push the J5 moment past its allowable value while the mass is well under the rating.

What payload ceiling should I set?

Use your company's design rule or the customer's machine specification. A lower ceiling keeps mass in reserve for heavier part variants or tooling added later, at the cost of a larger robot.

Where do I find the allowable wrist moment?

In the robot datasheet or mechanical manual, listed per wrist axis in N·m beside the allowable inertia in kg·m². Some makers publish load diagrams and sizing software instead.

How do I find the combined CoG of tooling and part?

Use CAD mass properties with the part modeled in the gripper, measured from the J5 axis. Without CAD, add up each item's weight times its distance from J5 and divide by the total weight.

Robotics & Automation calculator

Robot Payload Utilization Calculator

Check whether a robot carries your tooling and part, by mass against rated payload and by moment about the J5 wrist axis. You need both weights, the combined CoG distance and two datasheet ratings.

What this calculator does

Share of rated payload your tooling and part use, and whether the J5 wrist moment also fits.

Formula used

Load (kg) = tooling weight + part weight carried
Utilization (%) = load ÷ rated payload × 100; gap to ceiling = ceiling − utilization
Headroom (kg) = rated payload × ceiling ÷ 100 − load
J5 moment (N·m) = load × 9.80665 m/s² × CoG distance (mm) ÷ 1,000
Moment utilization (%) = J5 moment ÷ allowable × 100; farthest CoG (mm) = allowable × 1,000 ÷ (load × 9.80665)

Inputs explained

Tooling Weight: From the EOAT weight calculator or tool CAD.
Part Weight Carried: Heaviest part, or all parts held at once.
Rated Payload: Max load capacity at the wrist, from the datasheet.
Target Payload Ceiling: Your design rule or the customer's specification.
Load CoG Distance From J5: J5 axis to the CoG of tooling plus part, from CAD.
Allowable J5 Moment: Allowable load moment for J5, from the datasheet.

How to use the result

Best suited to choosing between two robot payload classes, adding a camera or tool changer, quoting a heavier part on an installed robot.
Checks J5 only; repeat for J4 and J6 with their own lever arms and ratings. Load inertia is not checked; compare it with the datasheet allowable inertia. Passing does not replace the maker's load diagram or sizing software, which also cover main axes and dynamics.

Current U.S. benchmarks

Global copper trades at $13,543 per tonne (IMF via FRED, Jul 2026), up 38.6% in a year, and U.S. industrial electricity averages 9.77 cents per kWh. Both feed electrified-hardware unit economics.

Common questions

Can a load under rated payload still overload the wrist? Yes. Rated payload holds only inside the maker's load diagram. A long gripper or offset part can push the J5 moment past its allowable value while the mass is well under the rating.
What payload ceiling should I set? Use your company's design rule or the customer's machine specification. A lower ceiling keeps mass in reserve for heavier part variants or tooling added later, at the cost of a larger robot.
Where do I find the allowable wrist moment? In the robot datasheet or mechanical manual, listed per wrist axis in N·m beside the allowable inertia in kg·m². Some makers publish load diagrams and sizing software instead.
How do I find the combined CoG of tooling and part? Use CAD mass properties with the part modeled in the gripper, measured from the J5 axis. Without CAD, add up each item's weight times its distance from J5 and divide by the total weight.

Last reviewed 2026-10-01.