For this registered 5,000 BTU window-air-conditioner setup, plan for 1,175 W of continuous running capacity and 1,740 W of starting or surge capability. The scheduled loads reach 940 W before the modeled motor-start event.

These figures cover one window AC plus a refrigerator, four LED bulbs, a box fan, a router/modem and two phone chargers under the default schedule. They do not apply to a 12,000 BTU unit, central air conditioning or every possible window AC.

This is a planning estimate, not confirmation that a particular generator will work. A candidate generator's labeled continuous rating must meet or exceed the running target, and its surge rating must meet or exceed the starting estimate for the required duration. Voltage, frequency, receptacles and connection compatibility must also be checked separately.

Loads included in the estimate

This is a one-cooled-bedroom planning case, not a one-appliance calculation. At the scheduled peak, the loads are:

> Window air conditioner 530 W, Refrigerator 200 W, Box fan 130 W, LED light bulb ×4 60 W, Wi-Fi router + modem 20 W

The two phone chargers are enabled in the scenario but are not scheduled to be on at that peak. If every enabled AC load were running together, the load would be 970 W rather than the scheduled 940 W.

To determine whether this reference case matches your home, compare the defaults with each appliance's nameplate or manual. A nameplate is the label that lists the appliance's electrical requirements. Look for:

  • Running or input watts, shown as W
  • Supply voltage, shown as V
  • Current, shown as A
  • Frequency, shown as Hz
  • Starting watts, surge current or locked-rotor information, if listed

Treat a missing rating as unknown, not as zero. If your AC or refrigerator has different ratings, replace the defaults in the editable tool. Do not scale this result directly by BTU capacity.

What sets the running and starting requirements

Running and starting capacity answer different questions:

  1. Scheduled running demand: The modeled loads operating together reach 940 W.
  2. Planning running capacity: Applying this scenario's declared headroom policy produces a target of 1,175 W. This policy belongs to this calculation and is not a universal generator-sizing rule.
  3. Starting demand: At the modeled starting peak, 940 W is already running. The event driver is Refrigerator adds 800 W while starting. The resulting starting estimate is 1,740 W.

The refrigerator—not the window AC—sets the largest modeled starting event in this scheduled case. The estimate assumes that only one motor starts at a time, so it does not show what happens if the refrigerator and AC compressors try to restart together.

When you need to edit the estimate

Use the displayed result unchanged only if your appliance ratings and planned load combination reasonably match this 5,000 BTU reference case.

First decide which loads are essential for your outage plan. You might choose the window AC and refrigerator as essential, then treat the fan, router/modem, lights and phone charging as optional or schedule them for different times. That priority is your decision; the calculation does not assign it for you.

Edit the estimate when:

  • Your window AC is not the registered 5,000 BTU reference size or has different nameplate watts.
  • Your refrigerator has different running or starting requirements.
  • You need more lights, fans, chargers or network equipment.
  • Another appliance must operate at the same time.
  • You expect all enabled loads to run together instead of following the default schedule.

Letting optional loads take turns can reduce simultaneous running demand, but it does not remove the need to account for compressor starting. This page does not calculate a 12,000 BTU unit or whole-house central cooling; use ratings for the actual equipment instead.

Checks this estimate does not complete

This result is a demand estimate, not a generator-model match. No candidate generator continuous or surge rating was entered, so the capacity assessments remain unknown rather than passed or failed.

Before relying on a generator, verify these separate constraints:

  • Voltage and frequency: The resolved scenario does not supply them. Read the AC and refrigerator nameplates and compare them with the generator's labeled outputs and manual.
  • Receptacle and connection arrangement: Watt capacity alone does not establish that the appliances can be connected appropriately.
  • Surge duration: The calculation provides a peak-watt estimate but not how long the generator must sustain it.
  • Coincident restarts: The calculation assumes one motor starts at a time. It does not prove that both compressor appliances can restart together.
  • Automatic restart behavior: The scenario does not establish how either appliance responds after power loss, overload or generator recovery.

The schedule is an editorial planning assumption, not a measurement from your home. The estimate also does not determine fuel use, generator runtime or whether the 5,000 BTU AC can maintain a safe or comfortable bedroom temperature.

What to check before choosing a generator

Use this sequence to compare a generator with your actual load list:

  1. Copy the running watts, voltage and frequency from the window AC and refrigerator nameplates or matching manuals.
  2. Find model-specific starting information where available. Do not invent a starting multiplier when that information is missing.
  3. Correct the editable load list and decide which optional loads truly need to operate at the same time.
  4. Compare the resulting running target with the generator's continuous or rated watts.
  5. Compare the resulting starting estimate with the generator's surge or starting watts, including any stated time limit.
  6. Confirm voltage, frequency, receptacle and connection compatibility separately.

For the unchanged reference setup, the two key planning thresholds are 1,175 W continuous and 1,740 W starting. If either candidate-generator rating is absent, compatibility remains unknown.