Room Dimension & Area Calculator

Before you buy flooring, paint or size an HVAC unit, you need the room’s real dimensions. The Room Dimension & Area Calculator turns length, width and height into floor area, perimeter, wall area, ceiling area and volume — in feet or meters, for one room or many identical ones.

Use the wall area for paint and the floor area for flooring takeoffs, switch units to match your plan, and export the results for ordering. Subtract doors and windows from the gross wall area for a true paint number.

• Core outputs: Floor, ceiling, wall area, perimeter, volume.
• Unit toggle: Feet or meters.
• Quantity: Multiply for identical rooms.
• Live: Updates as you type.
• Report & export: Copy or download as text, CSV or JSON.
• Learning guide: Formulas and uses.

1. Pick unit. Feet or meters.
2. Enter length, width, height. Inside dimensions.
3. Set quantity. Number of identical rooms.
4. Read outputs. Floor, walls, volume, totals.
5. Export. Copy or download.

Example 1 — Bedroom. 12×10×8 ft: floor 120 ft², walls 352 ft², volume 960 ft³.

Example 2 — Two rooms. Same ×2: floor 240, walls 704, volume 1,920.

Example 3 — Metric. 4×3.5×2.6 m: floor 14 m², walls 39.2 m², volume 36.4 m³.

Example 4 — Paint net. 352 ft² walls − 1 door (21) − 2 windows (30) = 301 ft² to paint.

Example 5 — Flooring. 120 ft² floor + 10% waste = 132 ft² ordered.

• One entry, many outputs: Floor, walls, volume at once.
• Takeoff-ready: Match flooring and paint to the room.
• Unit-flexible: Feet or meters on demand.
• Private: No account, nothing uploaded.