Power calculator (load) of apartment / house
Calculate the total power of electrical appliances in an apartment or house — consumption audit with recommendation for main circuit breaker and cable cross-section.
⚡ Object type
➕ Add appliance
📊 Result
Formula for calculating total load
Ku — simultaneity factor (0.5–1.0)
Typical power of household appliances
| Appliance | Power, W | Note |
|---|---|---|
| Refrigerator | 100–200 | Average — 150 W |
| Washing machine | 1800–2500 | Peak at heating |
| Electric kettle | 1800–2200 | Short-duration use |
| Electric oven | 2000–3500 | Separate circuit 16A |
| Air conditioner (small) | 700–1200 | Starting current ×3.5 |
| Microwave | 900–1500 | Short-duration use |
| Water heater 80L | 1500–2000 | Separate circuit |
| Dishwasher | 1800–2400 | Peak at heating |
| Iron | 1500–2400 | Cyclic load |
| TV (55") | 80–150 | Continuous |
Calculation example for a 2-room apartment
Installed power of a typical 2-room apartment: refrigerator 150 W + washing machine 2200 W + kettle 2000 W + oven 3000 W + air conditioner 1000 W + LED lighting 200 W + TV 120 W = 8670 W (~8.7 kW).
With a simultaneity factor of 0.65: P_calc = 8670 × 0.65 = 5.6 kW. Recommended input: 1 phase 32A, cable VVGng 3×6 mm².
How to calculate the power of an apartment or house?
Correct power calculation is the first step to designing an electrical panel. It determines the choice of the main circuit breaker, cable cross-section, and connection type (single-phase or three-phase).
Installed power is the sum of the rated powers of all appliances. The calculated power takes into account the simultaneity factor: in practice, not all appliances operate at full power simultaneously. For an apartment, this factor is usually 0.6–0.7.
Starting power shows the peak load when electric motors (compressors, pumps, air conditioners) start. It is important to check that the main circuit breaker does not trip during simultaneous startup.
After determining the total power, the next step is to distribute consumers into groups (circuits) of the panel. Each high-power point (electric stove, water heater, air conditioner) should have a separate circuit with an appropriate circuit breaker and cable. Calculate the cable cross-section for each circuit in the cable cross-section calculator.
For three-phase inputs, it is important to distribute consumers evenly across phases. Use our phase balance calculator to check that the imbalance does not exceed 15–20% according to IEC 60364.