Shore power load planning
RV shore power load calculator
Check whether a campground pedestal, driveway outlet, or adapter-limited hookup can carry your AC, charger, microwave, water heater, space heater, and kitchen loads at the same time.
Shore power load calculator
Check what your pedestal can carry before the breaker teaches the lesson.
Pick the available shore-power service, add the loads that may overlap, and include charger draw. The useful answer is not just total watts. It is which loads need to be timed, shed, or run alone.
Simultaneous AC loads
Include loads that can overlap. Mark the ones you would shed or only run alone.
Shore power check
This load stack is over the entered shore-power service
30A RV service at 120V provides about 3,600W, while the entered stack is 4,850W. Shed at least 1,250W before relying on this overlap.
Service capacity
3,600W
30A x 1 leg
Continuous target
2,880W
80% planning target
Entered load
4,850W
135% of total service watts
Recommended service
50A RV service
Based on total watts, not 50A leg balance
Margins
Breaker margin
-1,250W
Compared with the full pedestal wattage.
Continuous margin
-1,970W
1,970W should move out of the sustained stack.
Load-shedding ideas
Turn down the converter or inverter-charger
900WCharging batteries is often the easiest sustained load to reduce while the AC, microwave, or water heater runs.
Shed Electric water heater
1,400WThis load is a good candidate to turn off first when breaker margin is tight.
Watch-outs
This is load-overlap planning, not an electrical approval. Follow RV, pedestal, adapter, EMS, breaker, cord, and appliance ratings before plugging in.
A dogbone adapter changes the plug shape; it does not create more amps. A 50A rig plugged into a 30A pedestal still needs to behave like a 30A rig.
Low pedestal voltage makes high-current loads harder on motors, compressors, chargers, and cords. Use an EMS or surge protector with voltage protection when possible.
Recommended next move
Move high-draw appliances out of the same time window, turn down the charger, or use a higher service before running this stack.
Why this exists
Shore-power problems usually come from overlap, not one appliance.
A 30A pedestal can run plenty when loads are timed well, but the same pedestal can trip quickly when the air conditioner, charger, microwave, and water heater stack up. This calculator helps you decide what belongs in the same time window before a breaker or hot adapter makes the point.
Use this with
RV shore power guide
Use this when you need the 30A vs 50A basics, adapter limits, and safe hookup habits.
Open next stepBest RV surge protectors
Use this after the load math to choose protection against bad pedestal conditions.
Open next stepGenerator size calculator
Use this when the same appliance stack also needs to run from a portable generator.
Open next stepInverter size calculator
Use this if you are moving some AC loads to battery and inverter power instead.
Open next stepTool notes
What the shore-power estimate is actually saying
This output helps you decide whether a shore-power source has enough practical wattage for the loads you plan to overlap. It does not inspect pedestal wiring, cord condition, adapter quality, breaker health, voltage stability, or 50A leg balance.
Service watts
15A, 20A, and 30A service are treated as one 120V leg. 50A RV service is treated as two 120V legs for total watts.
Continuous target
The calculator multiplies service watts by your continuous-load target so long-running stacks do not sit right at breaker capacity.
Load stack
Appliance watts and battery-charger watts are added together, then compared with both the full service capacity and the continuous target.
Avoid these traps
Common mistakes before buying
Treating adapters like upgrades
A 50A-to-30A dogbone lets the plug fit, but the rig still has to behave like a 30A rig. The adapter does not create another 20 amps.
Forgetting charger draw
A converter or inverter-charger can quietly take hundreds or thousands of watts while batteries recover. That draw counts against the same pedestal as the AC and microwave.
Ignoring voltage
Low voltage makes tight shore-power plans rougher on motors, compressors, and cords. Breaker math is only one part of the safety picture.
Treat the calculator result as a planning range, then verify wiring, clearances, fusing, ventilation, and manufacturer limits before installation.See assumptions
Frequently asked
Questions RVers usually ask next.
Why does 50A RV service show so much more wattage than 30A?
A 30A RV hookup is usually one 120V leg, or about 3,600 watts at 120V. A 50A RV hookup is typically two 120V legs, or about 12,000 total watts, but this calculator does not verify whether loads are balanced across those two legs.
Should I use 80% as the continuous target?
Eighty percent is a conservative planning target for sustained loads like electric heat, water heating, charging, and air conditioning. Short bursts can sometimes exceed that, but a comfortable plan does not depend on running near the breaker for hours.
What should I enter for battery charger watts?
Use the AC input draw from your converter or inverter-charger manual if you have it. If you only know DC charging output, divide charge watts by roughly 0.82 to 0.90 and round up.
Can this replace an EMS or surge protector?
No. This is load planning only. A proper EMS or surge protector checks conditions this calculator cannot see, including high/low voltage, wiring faults, and pedestal problems.