Room Area & Volume Calculator
Comprehensive 3D room planner for floor area, ceiling, walls, room volume, and recommended AC cooling tonnage.
1. Room 3D Dimensions
Spatial Dimensions & Surface Areas
HVAC Tonnage Sizing Breakdown
AC sizing is calculated using room volume, window thermal transmission, and solar heat gain:
- • Base room sensible heat load: ~25 BTU per sq ft of floor area.
- • Ceiling height multiplier for high ceilings > 9.5 ft.
- • Solar radiation heat buffer applied for top floor or west-facing rooms.
Quick AC Sizing Matrix
- • Up to 120 sq ft: 1.0 Ton AC (12,000 BTU)
- • 120 – 180 sq ft: 1.5 Ton AC (18,000 BTU)
- • 180 – 250 sq ft: 2.0 Ton AC (24,000 BTU)
- • 250 – 350 sq ft: 2.5 Ton AC (30,000 BTU)
How to Use Room Area & Volume Calculator
- Enter room dimensions: Length, Width, and Ceiling Height in feet or meters.
- Select room insulation level and sun exposure (Low, Moderate, High Sun / Top Floor).
- View the comprehensive surface area breakdown: Floor Area, Ceiling Area, Wall Area, and Perimeter.
- Check total 3D Room Volume in Cubic Feet (ft³) and Cubic Meters (m³).
- Review the recommended Air Conditioner (AC) Cooling Tonnage (1.0 Ton, 1.5 Ton, 2.0 Ton) and BTU/hr requirements.
Key Features & Privacy Guarantee
- Complete 3D Spatial Calculation: Instantly computes Floor Sq Ft, Ceiling Sq Ft, 4-Wall Surface Area, and Total Air Volume.
- HVAC & AC Tonnage Estimator: Calculates required British Thermal Units (BTU/hr) and Air Conditioner tonnage sizing.
- Sunlight & Floor Exposure Multiplier: Adjusts cooling load for top floors, direct sunlit glass windows, and warm climates.
- Dual Metric & Imperial Engine: Switch smoothly between feet/inches and meters/centimeters.
- 100% Client-Side & Private: Real-time responsive calculations inside your browser.
Frequently Asked Questions
How do you calculate the volume of a room?
Multiply room length by width by ceiling height. Formula: Volume = Length × Width × Height. For example, a 15 ft × 12 ft room with a 10 ft ceiling has a volume of 1,800 cubic feet (approx 51 m³).
What AC tonnage do I need for my room size?
• Up to 120 sq ft: 1.0 Ton (12,000 BTU) • 120 to 180 sq ft: 1.5 Ton (18,000 BTU) • 180 to 250 sq ft: 2.0 Ton (24,000 BTU) • Top floor rooms or heavy sunlight exposure require an additional 0.5 Ton buffer.
What is the formula for total wall surface area?
Total Wall Area = 2 × (Length + Width) × Ceiling Height. For a 14×12 ft room with 10 ft height: 2 × (14 + 12) × 10 = 520 sq ft.
How many BTUs are in 1 Ton of refrigeration/air conditioning?
1 Ton of cooling capacity equals exactly 12,000 BTU/hr (British Thermal Units per hour) or approximately 3.517 kW.