FREE ONLINE TOOL

Square Foot Calculator Draw

Draw a shape on a canvas to calculate its square footage. Click to place points, close the shape, and see the area in square feet instantly.

Formula: Shoelace Formula on drawn points

Draw to Calculate

Click on the canvas below to place corner points. The area is calculated using the Shoelace formula. Set the scale (pixels per foot) first.

Total Area
0sq ft

How to Calculate Square Footage by Drawing

This interactive tool lets you draw any shape directly on a canvas and calculates the enclosed area. It's ideal for quick estimates of irregular areas when you don't have exact measurements.

How to Use

  1. Set the scale — determine how many pixels equal 1 foot (default is 20).
  2. Click on the canvas to place corner points of your shape.
  3. Place at least 3 points to form a closed shape.
  4. Click "Calculate Area" to compute the square footage.

Determining Scale

If you know one dimension of the area (e.g., a wall is 20 feet long), draw that wall and count the pixels, then divide pixels by 20 to get your scale factor.

Tips for Accuracy

  • Place points precisely at corner positions.
  • Use "Clear" to start over if you make a mistake.
  • More points along curved boundaries improves accuracy.
  • For complex shapes, break into sections and calculate separately.
Common Questions

Frequently Asked Questions

How does the drawing calculator work? +

Click on the canvas to place corner points of your shape. Set the scale (pixels per foot) first. The calculator uses the Shoelace formula on the drawn points.

How do I determine the right scale? +

If you know one dimension, draw that edge and count pixels. Divide pixels by the known distance in feet to get your scale factor.

How many points do I need? +

At least 3 points to form a triangle. More points give more accurate shapes. Add extra points along curved boundaries.