CoolCalc AI - Smart AC Tonnage Calculator
AI-powered AC calculator for all of India. Get perfect AC size, electricity costs & ROI analysis in seconds!
CoolCalc AI
Smart AC Size Calculator - Get perfect AC recommendations in seconds with AI-powered analysis for your space.
*📏 Room Dimensions (Required)
Enter your room measurements to get started
🎯 Additional Parameters (Optional but Recommended)
💡 Tip: Fill room dimensions above to use these buttons
🧮 Indian Practical Formula (100 BTU/sq ft)
Base: Area × 100 BTU/sq ft (Indian practical reference: ~120 sq ft = 1 TR)
Formula: Total BTU = (Base × Ceiling Factor × Sun × Floor) + Occupancy + Appliances
- • Ceiling: +10% per foot above 8 ft (e.g., 10 ft = +20%)
- • Sun: Low (North/Shaded) 0.95 | Moderate (East) 1.05 | High (West/South) 1.15
- • Floor: Top +10% | Middle 0% | Ground -5%
- • Occupancy: Auto-detect (1 person per 100 sq ft), +600 BTU per additional person
- • Appliances: Kitchen ~1000W (3412 BTU) | Normal ~300W (1024 BTU) | Low 0 BTU
- • Standard Sizes: Result rounded to 0.75, 1.0, 1.5, 2.0, 2.5, 3.0 TR
Quick reference: Up to 120 sq ft → 1 TR | 120-180 → 1.5 TR | 180-240 → 2 TR | 240-350 → 2.5 TR
How to Calculate AC Tonnage for Your Room
Choosing the right AC tonnage is crucial for optimal cooling, energy efficiency, and electricity bills. An undersized AC will struggle to cool your room, while an oversized AC will cycle on and off frequently, wasting electricity and causing uneven cooling.
Understanding AC Tonnage
AC tonnage refers to the cooling capacity of an air conditioner. One ton equals 12,000 BTU (British Thermal Units) per hour. In India, residential ACs typically range from 0.75 ton to 2 tons.
Quick Reference Guide:
- 0.75 Ton: Small rooms up to 80 sq ft (8x10 feet)
- 1.0 Ton: Small to medium rooms 80-120 sq ft (10x12 feet)
- 1.5 Ton: Medium rooms 120-180 sq ft (12x15 feet) - Most Popular!
- 2.0 Ton: Large rooms 180-250 sq ft (15x16 feet)
- 2.5 Ton: Very large rooms or halls 250+ sq ft
Factors That Affect AC Tonnage Requirements
1. Room Size (Most Important)
The primary factor is your room's area (length × width). As a rule of thumb, you need approximately 20-25 BTU per square foot for moderate climates. For Ahmedabad and Gujarat's hot climate, we recommend 25-30 BTU per square foot.
2. Number of Occupants
Each person in the room generates approximately 600 BTU of heat. A bedroom for 2 people needs more cooling capacity than a single-person room of the same size.
3. Sun Exposure & Window Direction
Rooms facing west or south receive maximum sunlight in Ahmedabad, especially during summer afternoons. These rooms can need 30-40% more cooling capacity. North and east-facing rooms need less cooling.
4. Floor Level
Top floor: Needs 20-25% extra capacity due to direct roof heat exposure
Middle floors: Standard calculation applies
Ground floor: Needs 5-10% extra capacity
5. Ceiling Height
Standard calculations assume 8-10 feet ceiling height. For higher ceilings (11-12 feet), add 15-20% more capacity as there's more air volume to cool.
6. Appliances & Heat-Generating Equipment
Kitchen: Add 4,000 BTU for stove and appliances
Living room: Add 1,000-1,500 BTU for TV, computer, etc.
Bedroom: Add 500-1,000 BTU for basic electronics
AC Tonnage Formula for Ahmedabad & Gujarat
Basic Formula:
BTU Required = (Room Area in sq ft × 25) + (Number of people × 600) + Heat Load Adjustments
Tonnage: BTU ÷ 12,000 = AC Tonnage
Common Room Sizes & AC Requirements in Ahmedabad
| Room Size | Area (sq ft) | Recommended AC | Price Range |
|---|---|---|---|
| 8×10 feet | 80 sq ft | 0.75 - 1.0 Ton | ₹25,000 - ₹35,000 |
| 10×12 feet | 120 sq ft | 1.0 - 1.5 Ton | ₹28,000 - ₹45,000 |
| 12×12 feet | 144 sq ft | 1.5 Ton ⭐ | ₹35,000 - ₹55,000 |
| 12×15 feet | 180 sq ft | 1.5 - 2.0 Ton | ₹38,000 - ₹60,000 |
| 15×16 feet | 240 sq ft | 2.0 Ton | ₹45,000 - ₹70,000 |
| 16×18 feet | 288 sq ft | 2.5 Ton | ₹60,000+ |
Should You Choose Inverter or Non-Inverter AC?
For Ahmedabad's climate where ACs run 6-8 hours daily in summer, we strongly recommend 5-star inverter ACs. Here's why:
✓ Inverter AC Benefits
- • Saves 30-40% on electricity bills
- • Maintains consistent temperature
- • Quieter operation
- • Longer compressor life
- • Better for Gujarat's long summers
- • Recovers cost in 2-3 years
⚠ Non-Inverter AC
- • ₹8,000-₹12,000 cheaper upfront
- • Good for occasional use
- • Higher electricity bills
- • On-off cycling
- • Less suitable for daily use
- • Recommended only for guest rooms
Common Mistakes to Avoid
- ❌ Buying oversized AC: "Bigger is better" is wrong! An oversized AC cools too quickly, cycles frequently, and wastes electricity while causing humidity problems.
- ❌ Ignoring sun exposure: A west-facing room in Ahmedabad needs 30% more capacity than a north-facing room.
- ❌ Forgetting top floor heat: Top floor rooms need at least 20% more cooling capacity.
- ❌ Not considering people: A bedroom for 2 adults + 1 child needs more tonnage than a single-person room.
- ❌ Choosing based on price alone: A ₹10,000 cheaper non-inverter AC costs ₹2,500 extra per year in electricity.
Why Choose System Designing for Your AC Purchase?
With 30+ years of experience installing 5000+ ACs across Ahmedabad and Gujarat, we know exactly what works in our climate:
- ✓ Free Home Visit: We measure your room and assess all factors personally
- ✓ Honest Recommendations: We'll never oversell you a bigger AC
- ✓ Authorized Dealer: Hitachi, Mitsubishi, BlueStar, Midea, Toshiba
- ✓ Expert Installation: Proper installation ensures optimal performance
- ✓ Post-Sales Support: AMC plans from ₹2,500/year
- ✓ 5.0★ Rating: 130+ verified Google reviews
Need Expert Help Choosing Your AC?
Get a free home visit and personalized AC recommendation from our 30-year experienced team
Frequently Asked Questions
Q: What tonnage AC for 12x12 room in Ahmedabad?
A: For a standard 12x12 feet room (144 sq ft) in Ahmedabad, a 1.5 ton AC is ideal. If it's a top floor or west-facing room, consider 1.5 ton inverter AC with good ISEER rating.
Q: Is 1 ton AC enough for 150 sq ft room?
A: For Gujarat's hot climate, 150 sq ft rooms need 1.5 ton AC minimum. A 1 ton AC will struggle during peak summer (45°C days) and won't cool efficiently.
Q: How many BTU per square foot in Ahmedabad?
A: We recommend 25-30 BTU per square foot for Ahmedabad's climate, compared to 20 BTU for moderate climates. This accounts for 45°C+ summer temperatures.
Q: Should I buy inverter or normal AC for daily use?
A: Always choose 5-star inverter AC for daily use (6+ hours). Despite ₹10,000 higher cost, you save ₹2,000-3,000 per year on electricity. It recovers the cost in 3-4 years.
Q: What happens if AC tonnage is too high?
A: An oversized AC cools the room quickly but creates humidity problems, cycles on-off frequently (wasting energy), and causes uneven cooling. Always size correctly.
Q: Which AC brand is best for Gujarat heat?
A: Hitachi, Mitsubishi Heavy Industries, and Daikin perform best in extreme heat (45°C+). BlueStar is excellent for commercial use. All are available at System Designing.