The average cost to replace an electrical panel is $850 to $1,100 for 100 amps, or $1,200 to $1,600 is a new service panel is needed. To upgrade to 200 amps, expect to spend $1,300 to $2,500, or $2,000 to $4,000 to upgrade to 400 amps. A low-amp subpanel costs $500 to $1,000.Click to see full answer. Also asked, how much does it cost to convert 100 amp to 200 amp? TOTAL COST TO UPGRADE Amperage Costs 100 $800 to $1,200 or $1,500 to $2,500 if a new box is needed 200 $1,300 to $3,000 400 $2,000 to $4,000 Also, do I need to upgrade to 200 amp service? 200 Amps is the minimum recommended service panel size in full size modern homes. Some situations will require significantly more. Larger homes or homes with a machine shop or car lift in the garage can require as many as 400 amps. Keeping this in consideration, do I need a permit to change my electrical panel? Simple electrical work such as replacing a bad outlet, installing a fixture, or replacing a fan does not require a permit. It is the for those bigger jobs, the kind that most of us would be afraid to do for fear of getting electrocuted, a permit and inspector are required.Can I put a 200 amp breaker in a 100 amp panel?You cannot put a 200 amp main breaker panel on a 100 amp service, unless the service is protected at 100 amps.