Name the interface before doing arithmetic
Write down where the cargo is carried: roof, hitch receiver, bed, or another mount. Then record the manufacturer’s terms and limits for that interface. Keep roof dynamic, roof static, hitch tongue/vertical, carrier, and cargo weights separate.
The Bing result that generated one click still does not turn mixed terminology into a universal rule. The safest comparison is the weakest confirmed limit for the actual system and use condition.
Limits
No vehicle, receiver, rack, carrier, or load was tested. Exact definitions vary by manufacturer and vehicle configuration.
Sources and related reading
See Also
If you want to move from general advice into actual product choices, start with Can a Kayak Stay on Crossbar Pads Overnight?, Cargo Basket Extension Compatibility: Weight, Bar Spread, and Overhang, and Cargo Basket Weight Distribution Habits for Stable Transport: What to Know Before You Haul.
For a wider picture after the basics, Universal vs. Vehicle-Specific Kayak Roof Racks: Key Differences and How to Choose and Extang Trifecta 2.0 Tonneau Cover Review: Fit, Features, and Trade-Offs are the next places to read.