Calculate the exact air conditioning capacity for any room in tons (TR), BTU/hr and kW — supports 80+ countries with climate-specific sizing
1
Location & room
2
Size & height
3
Loads & factors
❄ Step 1 — Location & Room Type
Select your country
Room type & occupants
📏 Step 2 — Room Size & Ceiling Height
Unit system
Room dimensions
Quick ceiling heights
Enter dimensions above to see room area
⚙ Step 3 — Loads & Factors
Insulation & windows
Equipment & appliance heat load
🖥 Computers / workstationsunits
🗇 Servers / rack unitsunits
🖶 Printers / copiersunits
📺 TVs / large displaysunits
💡 Lighting loadW
🔌 Other equipmentW
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Tons of Refrigeration (TR)
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Tons (TR)
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BTU / hr
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Kilowatts (kW)
Load Breakdown
🏠 Envelope / walls—
☀️ Window solar gain—
👥 Occupants—
🖥️ Equipment & lighting—
∑ Total heat load—
Recommended AC sizes
Worldwide AC Size Reference Guide
Area (sq ft)
Area (m²)
Mild climate
Hot climate
Very hot (Gulf)
Up to 120
Up to 11
0.75 ton
1.0 ton
1.0–1.5 ton
120–180
11–17
1.0 ton
1.5 ton
1.5–2.0 ton
180–280
17–26
1.5 ton
2.0 ton
2.0–2.5 ton
280–400
26–37
2.0 ton
2.5 ton
2.5–3.0 ton
400–550
37–51
2.5 ton
3.0 ton
3.5–4.0 ton
550–750
51–70
3.0 ton
4.0 ton
4.0–5.0 ton
750–1000
70–93
4.0 ton
5.0 ton
5.0–6.0 ton
1000–1500
93–139
5.0 ton
6.0–7.5 ton
7.5–10 ton
1500+
139+
Consult a certified HVAC engineer
How to Calculate AC Tonnage — Complete Guide
AC tonnage refers to the cooling capacity of an air conditioning unit. 1 ton of refrigeration (TR) equals 12,000 BTU per hour or 3.517 kW. Choosing the right AC size is critical — an undersized unit cannot cool the space, while an oversized unit short-cycles and wastes energy.
BTU Factor: 20 BTU/sq ft for bedrooms, 24 for offices, 30 for kitchens, 45 for server rooms
Climate Multiplier: 0.85 for UK, 1.0 for moderate, 1.25 for hot, 1.35 for UAE/Gulf
Occupant Load: 600 BTU per person
Window Load: 1,000 BTU per window
Equipment Load: Watts × 3.412 = BTU/hr
AC Sizing for UAE and Gulf Countries
In the UAE, Saudi Arabia, Qatar, and Kuwait, outdoor summer temperatures regularly reach 45–50°C. This means AC systems must work much harder than in moderate climates. A climate multiplier of 1.30–1.35 is applied, meaning you need 30–35% more cooling capacity than the base calculation for the same room size.
Why Equipment Load Matters
In offices and server rooms, computers, servers, and lighting generate significant heat that must be removed by the AC system. A typical office with 10 computers adds approximately 8,500 BTU/hr (0.7 tons) of additional cooling load. Always include equipment loads for accurate sizing.
AC Tonnage Calculator — Frequently Asked Questions
How do I calculate AC tonnage for my room? ⌄
Multiply room area (sq ft) by a base BTU factor (20–45 depending on room type), apply a climate multiplier for your country, add occupant load (600 BTU each), window gains (1,000 BTU each), and equipment loads. Divide the total by 12,000 to get tons. Always add a 10–15% safety margin.
What is 1 ton of AC in BTU and kW? ⌄
1 ton of refrigeration = 12,000 BTU/hr = 3.517 kW. Common sizes: 0.75 ton (9,000 BTU), 1 ton (12,000 BTU), 1.5 ton (18,000 BTU), 2 ton (24,000 BTU), 2.5 ton (30,000 BTU), 3 ton (36,000 BTU), 5 ton (60,000 BTU).
How many sq ft does 1 ton AC cover in UAE? ⌄
In UAE and Gulf countries where temperatures reach 45–50°C, 1 ton covers approximately 280–320 sq ft. In mild UK climates, 1 ton covers 400–600 sq ft. Always use the country-specific climate multiplier for accurate sizing.
Should I include equipment load in my AC calculation? ⌄
Yes — especially for offices and server rooms. A desktop PC adds ~250W (853 BTU/hr), a server adds ~500W (1,706 BTU/hr), and lighting adds 3.412 BTU per watt. In a fully equipped office, equipment can account for 30–50% of the total cooling requirement.
What size AC for a 500 sq ft office in Dubai? ⌄
For a 500 sq ft standard office in Dubai with 4 occupants, you typically need 2.0–2.5 tons (24,000–30,000 BTU/hr). The UAE climate multiplier of ×1.35 accounts for extreme outdoor temperatures reaching 48°C in summer months.
Is it better to oversize my AC unit? ⌄
No — oversizing causes short cycling, poor humidity control, higher energy bills, and shorter equipment life. An oversized AC cools quickly but cannot dehumidify properly. Size within 10–15% of the calculated load and go to the next standard size only if needed.
What is the difference between split AC and central AC tonnage? ⌄
The tonnage calculation method is the same for both. Split ACs typically come in 0.75 to 3 ton sizes and serve individual rooms. Central AC systems can range from 5 to 50+ tons and serve entire buildings. Use this calculator for individual rooms, then sum up for total building tonnage.
How does ceiling height affect AC tonnage? ⌄
Higher ceilings mean more air volume to cool. A room with a 14 ft ceiling has 40% more volume than the same room with a 10 ft ceiling. This calculator applies a height adjustment factor for ceilings above 10 ft to ensure accurate sizing for warehouses, halls, and high-ceiling spaces.
This calculator provides estimated cooling loads based on standard HVAC guidelines. For large, complex, or critical spaces (server rooms, hospitals, cleanrooms), always consult a certified HVAC engineer for a full heat load analysis.
