# How many ton AC do I need? Room size chart for India (2026)

> 1 ton for rooms up to ~120 sq ft, 1.5 ton for 120–180 sq ft, 2 ton for 180–250 sq ft. Adjust for top floors, sun and city heat. Plus star ratings, inverter ACs and running costs.

- URL: https://2search.in/knowledge/articles/oct-26/which-ac-ton-for-room-india
- Genre: Heating & cooling
- Country: India
- Published: 2026-10-27
- Updated: 2026-10-27
- Publisher: 2search (https://2search.in)

> **Quick answer:** For a typical Indian room with a normal 9–10 ft ceiling: **1 ton for up to ~120 sq ft**, **1.5 ton for ~120–180 sq ft**, **2 ton for ~180–250 sq ft**. Go **one size up** for **top-floor rooms**, **west-facing walls**, **big windows**, **very hot cities (40°C+)**, a kitchen next door or **more than 3–4 people** in the room. Choose an **inverter AC** with a **3-star or 5-star** BEE label — and note that the star rating bar was raised from **1 January 2026**.

> **Key takeaways**
> - Size by **room area and heat load**, not just "1.5 ton is standard".
> - An **undersized AC** runs flat out and never cools; an **oversized** one cools fast but leaves the room damp and wastes money.
> - A **1.5-ton 5-star inverter AC** uses roughly **0.9–1.2 units an hour** in normal use — about **₹7–₹10 an hour** at ₹8/unit.
> - From **2026**, a new 3-star AC is roughly as efficient as an old 4-star — compare **ISEER** numbers, not just stars.
> - Set it to **24–26°C**; each degree lower adds about **6%** to power use.

Buying the wrong size AC is the most common and most expensive mistake. This guide gives you a quick size chart, a simple way to adjust for your home, a clear explanation of star ratings and inverter technology, and the real running cost so you can choose with confidence.

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![How many ton AC do I need? Room size chart for India (2026) Breakdown & Visual Guide](/images/articles/which-ac-ton-for-room-india/diagram.svg)

## AC size chart by room size

| Room size | Example dimensions | Normal room | Hot / top floor / sunny / 40°C+ city |
| --- | --- | --- | --- |
| Up to 100 sq ft | 10×10 ft | 0.75–1 ton | 1 ton |
| 100–120 sq ft | 10×12 ft | **1 ton** | 1.5 ton |
| 120–150 sq ft | 12×12 ft | **1.5 ton** | 1.5 ton |
| 150–180 sq ft | 12×15 ft | **1.5 ton** | 2 ton |
| 180–220 sq ft | 14×15 ft | **2 ton** | 2 ton |
| 220–250 sq ft | 15×16 ft | **2 ton** | 2.5 ton or two units |
| 250+ sq ft (hall) | 16×18 ft+ | 2.5 ton or two units | Get a site check |

**Ton** here is cooling capacity, not weight. 1 ton ≈ **3.5 kW** (12,000 BTU per hour) of cooling.

## Adjust for your room: the heat checklist

Add **0.5 ton** (one size up) if **two or more** of these apply:

- ☐ **Top floor** or roof directly above (no other flat above you)
- ☐ **West or south-facing** wall that gets afternoon sun
- ☐ **Large windows** or glass doors, especially without curtains or film
- ☐ City summers above **40–42°C** (Delhi, Nagpur, Ahmedabad, Jaipur, Lucknow, etc.)
- ☐ **More than 3–4 people** regularly in the room
- ☐ **Kitchen** next to it or heat-producing equipment (gaming PC, many lights)
- ☐ **High ceiling** (11 ft or more)
- ☐ Poor insulation or the AC must cool an **open area** connected to another room

> **Example:** A **12×14 ft (168 sq ft)** bedroom on the **top floor in Delhi** with a **west wall**. The chart says 1.5 ton, but two heat factors apply → choose **2 ton**. The same room on a middle floor in Bengaluru → **1.5 ton** is enough.

## Split vs window vs portable

| Type | Pros | Cons | Best for |
| --- | --- | --- | --- |
| **Split AC** | Quiet, efficient, better looks, inverter options | Higher price, installation cost | Bedrooms, living rooms |
| **Window AC** | Cheaper, simple install, one unit | Noisy, needs a window opening, fewer inverter models | Budget, rented homes |
| **Portable AC** | No installation, movable | Least efficient, noisy, needs a duct | Temporary use |

## Inverter vs non-inverter AC

An **inverter AC** changes its compressor speed to match the room's needs, while a **fixed-speed** AC switches fully on and off.

- Inverter ACs use **30–50% less power** in typical long-hour use.
- Temperature stays **steady**, with less noise.
- Nearly all **split ACs** sold today are inverter models.

If you use the AC more than **4–5 hours a day**, inverter is clearly worth it.

## Star ratings and ISEER (2026 update)

BEE star ratings use **ISEER** (Indian Seasonal Energy Efficiency Ratio) — cooling delivered per unit of electricity over a typical Indian season. **Higher ISEER = lower bills.**

From **1 January 2026**, BEE raised the thresholds by roughly **10–14%**:

- A **2026 3-star** AC is about as efficient as a **2025 4-star**.
- A **2026 5-star** split AC needs a much higher ISEER than before.

So when comparing models, **look at the ISEER number** on the label, not only the stars.

### 3-star vs 5-star: is it worth paying more?

> **Example:** A 1.5-ton split AC used **8 hours a day for 6 months** (~1,440 hours a year) at **₹8 per unit**:
> - 3-star (ISEER ~4.3): about **1,350 units a year** → **~₹10,800**
> - 5-star (ISEER ~5.6): about **1,050 units a year** → **~₹8,400**
> - Savings: **~₹2,400 a year**. If the 5-star costs ₹6,000 more, payback is about **2.5 years**.

If you use the AC a lot — or live in a very hot city — **5-star** is usually worth it. For a guest room used a few nights a year, 3-star is fine.

## Running cost: how much electricity does an AC use?

Rough real-world use for an **inverter split AC** at 24°C:

| AC | Units per hour (typical) | Cost per hour at ₹8/unit | 8 hours/night for 30 days |
| --- | --- | --- | --- |
| 1 ton, 5-star | 0.6–0.8 | ₹5–₹6.5 | ~₹1,200–₹1,550 |
| 1.5 ton, 3-star | 1.0–1.4 | ₹8–₹11 | ~₹1,900–₹2,700 |
| 1.5 ton, 5-star | 0.9–1.2 | ₹7–₹10 | ~₹1,700–₹2,300 |
| 2 ton, 5-star | 1.2–1.6 | ₹10–₹13 | ~₹2,300–₹3,100 |

Actual use depends on outside heat, room size, insulation and how long the compressor runs. Use your **electricity tariff slab** for accurate numbers.

## How to cut AC bills

- **Set 24–26°C.** BEE made **24°C the default** setting for new ACs. Each degree lower adds roughly **6%** to consumption.
- Use **sleep mode** or a timer at night.
- **Run a ceiling fan** on low with the AC — you'll feel cooler at a higher setting.
- **Clean filters** every 2 weeks in summer; get a full **service** before each season.
- Keep **doors and windows closed**; use curtains or reflective film on sunny windows.
- Install the **outdoor unit in shade** with good airflow — a hot outdoor unit works harder.
- Consider **rooftop solar** to offset daytime AC use — see [PM Surya Ghar subsidy](/pm-surya-ghar-rooftop-solar-subsidy).

## Buying checklist

1. ☐ Right **tonnage** for your room (chart + heat checklist)
2. ☐ **Inverter** split AC
3. ☐ **ISEER** on the 2026 BEE label (higher is better)
4. ☐ **Copper** condenser coil (easier to repair; better in coastal areas with anti-corrosion coating)
5. ☐ **Warranty:** 1 year product, 5 years PCB, 10 years compressor is common
6. ☐ **Installation cost** included? Check for extra copper pipe, stand and drainage charges
7. ☐ **Stabiliser-free** operating range if your voltage fluctuates
8. ☐ Noise level (indoor unit dB) for bedrooms

## Frequently asked questions

### Which ton AC is best for a 12×12 room?

A 1.5-ton AC for a normal 144 sq ft room. On a top floor or in a very hot city, 1.5 ton is still usually fine; 2 ton if there's heavy sun on the walls.

### Is a 1 ton AC enough for a 150 sq ft room?

Usually not in Indian summers. Choose 1.5 ton for 120–180 sq ft.

### Does a bigger AC use more electricity?

At full power, yes. But an undersized AC runs flat out for longer, so the right size is the most efficient choice.

### How many units does a 1.5 ton 5-star inverter AC use per hour?

Typically about 0.9–1.2 units an hour in real use at 24°C, depending on heat and room size.

### Is a 5-star AC worth it?

If you use the AC for many hours every summer, usually yes — the savings pay back the higher price in a few years.

### What temperature should I set my AC to?

24–26°C. It's comfortable for most people and saves electricity.

### Do I need a stabiliser for an inverter AC?

Most inverter ACs work across a wide voltage range. If your area has severe fluctuations, a stabiliser can still help protect the unit.

## Sources

- [Bureau of Energy Efficiency — Standards & labelling](https://beeindia.gov.in/)
- [Onida — 2026 BEE standards and energy savings](https://onida.com/blog/energy-efficiency-breakthrough-how-the-2026-bee-standards-deliver-superior-energy-savings-and-faster-cost-recovery-for-consumers/)
- [Business Today — 24°C default temperature for ACs](https://businesstoday.in/latest/economy-politics/story/mandatory-acs-default-temperature-setting-24-degrees-celsius-241961-2020-01-06)
- [Business Standard — India to standardise AC temperature 20–28°C](https://www.business-standard.com/india-news/india-standardise-air-conditioner-temperature-20-28-degree-celsius-125061001221_1.html)
- [LG India — What star ratings really mean when buying an AC](https://www.lg.com/in/magazine/what-star-ratings-really-mean-when-buying-an-ac-in-india/)