Choosing the right air conditioner size is one of the biggest headaches for homeowners in Singapore. The weather is consistently hot and humid throughout the year, so selecting the wrong BTU or horsepower (HP) can result in a home that is under-cooled, noisy, and has higher electricity bills.

If you’re planning to install a new air conditioner for your HDB, condo, or landed home, this guide explains the best size you should choose in simple, practical terms.

1. Why Aircon Size Matters in Singapore

Many people think buying a stronger air conditioner means better cooling. But too strong or too weak brings problems:

Too small =

• The room never gets cold
  
• Aircon runs continuously
  
• High electricity bills
  
• Faster wear and tear
  

Too big =

• Short cooling cycles
  
• The room becomes cold but humid
  
• Higher upfront cost
  
• More energy wasted
  

The right size gives efficient, fast, and comfortable cooling.

2. How to Calculate the Right Aircon BTU for Singapore Homes

In Singapore, the British Thermal Unit (BTU) is the standard for air conditioning sizing.
A simple formula:

Recommended BTU = Room Size (sq ft) × 60

Singapore climate is hot, so we use 60 BTU per sq ft as a reliable estimate.

3. Singapore Room Size Guide (HDB / Condo / Landed)

Below is a practical table most Singapore homeowners use:

Room Type	Approx. Size	Ideal BTU	Aircon HP
Small Bedroom	90–110 sq ft	5,000–7,000 BTU	1.0 HP
Common Bedroom	110–150 sq ft	7,000–9,500 BTU	1.0 HP
Master Bedroom	150–220 sq ft	9,500–12,000 BTU	1.5 HP
Living Room (HDB 3/4-room)	250–350 sq ft	15,000–18,000 BTU	2.0 HP
Living Room (Condo / Larger Units)	350–500 sq ft	18,000–24,000 BTU	2.0–2.5 HP

4. Factors That Affect Your Aircon Size

In Singapore, these extra conditions can change the BTU needed:

✔ Sun-facing unit (west sun)

Add 10–15% BTU

✔ High ceiling homes

Add 15% BTU

✔ Many people in the room

Add 600 BTU per extra person

✔ Lots of windows or glass walls

Add 15–20% BTU

5. Best Aircon Size for Popular Singapore Scenarios

Scenario A: 4-room HDB (Typical Layout)

• Bedrooms: 1.0 HP each
  
• Living Room: 2.0 HP
  
• System 3 or System 4 recommended
  

Scenario B: 3-room HDB

• Bedrooms: 1.0 HP
  
• Living Room: 1.5–2.0 HP
  
• System 2 or System 3
  

Scenario C: Condo with open living/dining area

• Living + Dining: 2.0–2.5 HP
  
• Bedrooms: 1.0 or 1.5 HP
  

Scenario D: Landed Property

• Choose based on room size
  
• Larger spaces may require multi-split or VRV system
  

6. Most Singaporeans Ask: “Can I run all units at once?”

If you install a System 3 / System 4 aircon, the outdoor compressor has a limit.
Running all units at maximum might reduce cooling power.

Tip: Choose a higher-capacity compressor if you want to run multiple rooms at once.

7. Summary: The Best Aircon Size for Your Home

Here’s a quick takeaway:

✔ 1.0 HP → Small/medium bedroom

✔ 1.5 HP → Master bedroom

✔ 2.0 HP → HDB/Condo living room

✔ 2.5 HP → Large living room / open concept

Choosing the right size ensures:

• Faster cooling
  
• Lower utility bills
  
• Longer aircon lifespan