The answer to 'how to know if your electrical panel needs upgrading' is that you should inspect your electrical panel regularly for signs that it needs to be replaced or upgraded. Some key indicators include the panel being more than 20-25 years old, having frequent circuit breaker trips, burning or discolored wiring or connections, or not having enough circuit breakers to accommodate your home's electrical needs.
Upgrading your electrical panel is an important safety measure that can prevent electrical fires and ensure your home has sufficient power capacity. It's recommended to have a licensed electrician inspect your panel every 5-10 years to assess its condition and determine if an upgrade is needed.