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AC Bill Calculator — Running Costs

Calculate hourly, daily, and monthly AC electricity bill cost based on tonnage, BEE star rating, and tariff.

Live 2026 Data
Standard Sizes 1.0 - 2.5 Ton
Hourly Run Cost ~₹6 - ₹12 / hr
Stars Supported 3-Star / 5-Star
Inverter Savings Up to 35% Save

1. Enter Configuration Parameters

Frequently Asked Questions (FAQ)

How does AC star rating affect power bills?

5-star inverter ACs consume up to 20-25% less power than 3-star inverter ACs, and up to 40% less than older 3-star non-inverter models because they adapt their compressor speed dynamically.

How much power does an AC consume per hour?

A typical 1.5 Ton 3-Star inverter AC draws about 1.0 to 1.2 kW per hour during active cooling. Over an 8-hour period, it consumes roughly 6 to 8 units (kWh) of electricity, depending on the temperature setting and ambient outdoor heat.

Is a 5-Star inverter AC worth the extra cost compared to a 3-Star AC?

Yes. A 5-Star inverter AC is roughly 15-20% more energy-efficient than a 3-Star AC, saving about 150-200 units annually. For a standard tariff of Rs. 8.00/unit, this translates to savings of Rs. 1,200 to Rs. 1,600 per year, offsetting the price premium in 2 to 3 years.

What temperature should I set my AC to for maximum savings?

Set your AC to 24°C or 25°C. According to the Bureau of Energy Efficiency (BEE), every degree increase in the AC temperature setting saves approximately 6% of electricity. Setting your AC to 24°C instead of 18°C can reduce your AC's power consumption by up to 36%.

How does tonnage relate to room size for air conditioning?

AC tonnage measures cooling capacity (1 Ton = 12,000 BTU/hr). Standard sizing rules: up to 100 sq ft requires a 1.0 Ton AC, 100–150 sq ft requires a 1.5 Ton AC, and rooms larger than 150 sq ft need a 2.0 Ton AC to cool effectively.

What is ISEER rating, and how do I read it?

Indian Seasonal Energy Efficiency Ratio (ISEER) measures the ratio of heat removed to the energy consumed over a typical year. A higher ISEER rating means higher efficiency. Currently, 5-Star ACs require an ISEER of 5.0 or above, while 3-Star ACs require 3.8 to 4.9.

Does running an AC in sleep mode actually save money?

Yes. Sleep mode automatically increases the set temperature by 1°C per hour for the first two hours (up to 2°C). This aligns with the natural drop in body temperature and ambient night temperatures, saving up to 10-15% of night power consumption.

About This Calculator

Target Audience: Homeowners & buyers sizing AC capacity and calculating energy consumption

What Does This Calculator Do?

This calculator estimates the monthly and yearly electricity bill contribution of running an air conditioner. It factors in tonnage, BEE star rating, daily hours, and state-specific tariffs.

How to Use It

  1. AC Tonnage: Select 1.0 Ton, 1.5 Ton, or 2.0 Ton.
  2. BEE Star Rating: Select 3-Star or 5-Star (Inverter/Non-Inverter).
  3. Hours of Use: Enter how many hours you run the AC daily.
  4. State Tariff (₹/unit): Input your local state electricity tariff rate.

The Logic Explained Simply

  • The Concept: Running an AC is the biggest driver of household power bills. Inverter ACs save energy by slowing down the compressor once the room is cool, whereas 5-star units draw less power than 3-star ones.
  • The Formula:
  • Average Power Draw (kW) = AC Tonnage Sizing Constant × Star Rating Coefficient
  • Daily Consumption (kWh) = Power Draw (kW) × Daily Hours
  • Monthly Cost = Daily Consumption × 30 days × Tariff Rate (₹/unit)

Real-World Calculation Breakdown

Assume you run a 1.5 Ton 5-Star Inverter AC (average draw ~1.0 kW) for 8 hours daily at an average tariff of ₹7.50 per unit:

  1. Daily Consumption: 1.0 kW × 8 hours = 8 units (kWh).
  2. Monthly Consumption: 8 units × 30 days = 240 units.
  3. Monthly Bill Cost: 240 units × ₹7.50 = ₹1,800.

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