Square Footage Calculator
Calculate the area of a single room, or add multiple rooms for a running total — with an optional cost estimate per square foot.
Add a row for each room or section — great for L-shaped rooms, whole-floor totals, or multi-room flooring projects.
How to Use the Square Footage Calculator
Works for a single room or an entire floor plan.
Add your first room
Enter a length and width. For irregular rooms, break the space into rectangular sections and add each one separately.
Add more rooms as needed
Click "+ Add Room" to include additional spaces — perfect for whole-floor totals or multi-room projects.
Get your total area
See the combined square footage instantly, plus an optional total cost if you enter a price per square foot.
How This Calculator Works
Basic area math, made easy for multi-room spaces.
📏 Length × width
Each room's area is simply length multiplied by width. For non-rectangular rooms, split the space into smaller rectangles, calculate each individually, and add them together.
➕ Automatic running total
Every room row you add is summed automatically, so you get one accurate total instead of manually adding up numbers on a separate calculator.
Measuring Tips
Getting accurate dimensions makes every downstream project easier.
✅ Measuring accurately
- Measure at floor level, wall to wall, not at baseboard height
- For L-shaped rooms, split into two rectangles and add both
- Round measurements to the nearest inch or centimeter for accuracy
⚠️ Common mistakes
- Forgetting closets, alcoves, or bay windows in the total
- Mixing units (feet in one row, meters in another)
- Using floor plan estimates instead of actual measurements
Frequently Asked Questions
Common questions about calculating square footage.
For a rectangular space, multiply the length by the width, both measured in feet. For irregular rooms, split the space into rectangular sections, calculate each separately, and add them together.
Calculate the area of each room individually using length times width, then sum all the individual areas together for the total square footage.
Multiply the area in square meters by approximately 10.764 to get the equivalent in square feet.
It depends on the purpose. For flooring or paint projects, include every space that needs the material. For real estate listings, standards vary by region on what counts as livable square footage.