The Room Square Meter Calculator gives the area of a room in square metres (m²) from its length and width in metres or centimetres. It also shows the area in square feet and the room perimeter, and can add up several rooms for a total floor area.
Room Square Meter Calculator
Room area in square metres (m²) from metres or centimetres, for one room or several rooms.
Area = length × width. If you measure in centimetres, the calculator converts for you — no need to divide by 10,000 yourself.
Formula
A = L × W (m²)
P = 2 × (L + W) (m)
Conversions: 1 m² = 10,000 cm² = 10.7639 ft².
How the Calculation Works
Step 1: Measure length and width in metres (or centimetres).
Step 2: Multiply them for the area.
Step 3: For several rooms, add each room’s area.
Example Calculation
One room
Given: 4.5 × 3.6 m
Area = 16.2 m² ≈ 174.4 ft²; perimeter = 16.2 m
Several rooms
Given: 4.5 × 3.6 m, 3.5 × 3 m and 2.5 × 2 m
Total = 16.2 + 10.5 + 5.0 = 31.7 m²
From centimetres
Given: 450 × 360 cm
Area = 162,000 cm² ÷ 10,000 = 16.2 m²
Square Metres to Square Feet
| m² | ft² |
|---|---|
| 10 | 107.6 |
| 15 | 161.5 |
| 20 | 215.3 |
| 25 | 269.1 |
| 30 | 322.9 |
Dimensions Explained
- For L-shaped or irregular rooms, split into rectangles and use the several-rooms tab.
- Flooring, paint and tiles are bought by coverage and pack size — area is the starting point, not the purchase quantity.
Frequently Asked Questions
How do I calculate square metres of a room?
Multiply the length by the width in metres.
How do I convert cm to m²?
Multiply length × width in cm, then divide by 10,000.
How big is a 12 m² room?
For example 4 × 3 m, or about 129 ft².
How do I convert m² to square feet?
Multiply by 10.764.
Is perimeter the same as area?
No — perimeter is the distance around the room in metres, used for skirting board and trim.