AC Capacity Calculator
Calculate the ideal air conditioning capacity in just 30 seconds. Enter your room parameters -- floor area, storey, insulation, orientation, number of occupants -- and our calculator will show you the exact kW value needed, recommended models, and estimated monthly operating costs.
AC Capacity Calculator
Calculate the required AC capacity in 30 seconds
Room size visualization
Recommended capacity
2.88 kW
Medium roomEstimated monthly electricity cost (cooling season)
~6,912 HUF
(SEER 7.0, 8h/day, 70 Ft/kWh)
How do we calculate?
Proper AC sizing is one of the most critical steps in creating an efficient cooling and heating system. Our calculator takes multiple factors into account to determine the required cooling capacity. The base calculation method relies on empty room volume, which is then modified by various correction factors.
The base formula
Q = A × 0.1 × Ffloor × Finsulation × Forientation + Qheight + Qpeople + Qflooring
Where:
- A -- room floor area in square metres (m2)
- 0.1 kW/m2 -- base value assuming a standard room with 2.6 metre ceiling height
- Ffloor -- floor level multiplier: ground (1.05x), middle (1.0x), top floor (1.15x). The top floor receives additional heat load from the sun-exposed roof in summer
- Finsulation -- insulation multiplier: poor (1.25x), average (1.0x), good (0.85x). Poorly insulated buildings require more cooling energy
- Forientation -- window orientation multiplier: south (1.15x), east/west (1.05x), north (0.95x). South-facing windows receive more solar radiation
- Qheight -- ceiling height correction: above 2.6 metres, additional capacity is needed due to the larger air volume
- Qpeople -- approximately 0.12 kW additional heat load per person (above 1 person)
- Qflooring -- floor type correction: stone and tile provide better cooling; carpet retains more heat
Example calculation
Consider a 30 m2 middle-floor room with average insulation, east/west orientation, 2.7 metre ceiling height, and 2 occupants:
Base: 30 × 0.1 = 3.00 kW
Floor: × 1.0 = +0.00 kW
Insulation: × 1.0 = +0.00 kW
Orientation: × 1.05 = +0.15 kW
Ceiling height: (2.7 - 2.6) × 0.05 × 30 = +0.15 kW
People: (2 - 1) × 0.12 = +0.12 kW
Total: ~3.42 kW → Recommended: 3.5 kW unit
Important notes on sizing
The online calculator provides an indicative result. For final sizing, numerous additional factors should be considered that can be assessed during an on-site survey:
- Electrical appliances -- computers, televisions, and lighting all generate heat. In an office with multiple computers, 20-30% higher capacity may be needed
- Kitchen heat sources -- ovens, hobs, dishwashers, and other kitchen equipment generate significant heat load
- Door and window condition -- old, unsealed windows and doors compromise insulation quality, causing additional heat loss
- Roof type -- flat roofs and pitched roofs have different thermal properties that affect cooling requirements
- External shading -- shutters, pergolas, trees, and other shading elements reduce the heat load caused by solar radiation
MAFER-COOL KFT offers a free on-site survey where our specialists consider all these factors and provide an accurate, personalised quotation. Call us at 06 30 972 1237 or email [email protected].
Typical AC sizes and room pairings
| Capacity (kW) | BTU | Ideal room (m2) | Typical application |
|---|---|---|---|
| 2.0-2.5 | 7,000-9,000 | 15-25 | Bedroom, small office |
| 3.0-3.5 | 10,000-12,000 | 25-35 | Living room, medium office |
| 5.0-5.3 | 17,000-18,000 | 35-50 | Large living room, lounge |
| 7.0-8.0 | 24,000-28,000 | 50-70 | Office space, retail shop |
Useful guides
Learn the details of choosing and using air conditioning
Frequently asked questions
About AC sizing and using the calculator
How does the calculator determine the required AC capacity?
How accurate is the online calculator result?
Why is proper AC sizing important?
What factors should I consider beyond capacity when choosing an AC?
How long does AC installation take after the survey?
How much does it cost to run an AC per month?
Want precise sizing? Call us!
We offer free on-site surveys and personalised quotations. MAFER-COOL KFT specialists will help you choose the perfect air conditioning system for your space.