The formula is simple: Cost = (Wattage ÷ 1000) × Hours per day × Rate per kWh. For example, a 1,500W air conditioner running 8 hours/day at RM 0.571/kWh costs about RM 6.85 per day — that's RM 205 per month.
Use the formula: Cost = (Wattage ÷ 1000) × Hours per day × Rate per kWh. For example, a 1,500W air conditioner running 8 hours/day at RM 0.571/kWh costs about RM 6.85 per day — roughly RM 205 per month.
TNB uses a tiered domestic tariff: first 200 kWh at RM 0.218/kWh, next 100 kWh (201–300) at RM 0.334/kWh, next 300 kWh (301–600) at RM 0.516/kWh, and above 600 kWh at RM 0.571/kWh.
A typical 1.5HP (~1,100W) AC running 8 hours a day costs roughly RM 5–7 per day, depending on your TNB tier. That's approximately RM 150–200 per month for one unit. Setting it to 24–25°C instead of 18°C can save 10–20% on cooling costs.
Air conditioners are the biggest consumer (900–2,500W), followed by water heaters (1,500–3,000W), refrigerators (100–400W running 24 hrs), washing machines (500–1,200W per cycle), and TVs (50–200W). Phone chargers and LED lighting have minimal impact compared to these.
The biggest savings come from your air conditioner — set it to 24–25°C, use auto-off timers, and clean filters regularly. Also: switch to LED bulbs, unplug standby devices, only run the washing machine with full loads, and consider a solar water heater for long-term savings.