Window Well
Prism volume for well; stone weight rough estimate.
Inputs
Results
Volume
78.75 ft³
≈ 15 bathtubs
Stone (~lb)7,875
How to Use This Calculator
- Enter the window opening width in inches — the well is sized 12 inches wider than the window.
- Enter the well projection in inches (how far it extends from the foundation wall).
- Enter the well depth in inches (measured from grade to the bottom of the well).
- Read the total well volume in cubic feet and the approximate drainage stone weight in pounds needed at the well bottom.
How the result changes with Projection (in)
| Projection (in) | Volume |
|---|---|
| 23 | 43.13 ft³ |
| 50 | 93.75 ft³ |
| 82 | 153.75 ft³ |
| 109 | 204.38 ft³ |
What each input means
- Window width (in)
- Width of the egress window opening in inches. The well will be sized 12 inches wider for clearance.
- Projection (in)
- How far the window well extends outward from the foundation wall, in inches.
- Depth (in)
- Depth of the window well from grade to bottom, in inches. Must meet local egress code requirements.
How this is calculated
Worked example, using the default values
- Identify Input ParametersWindow width (in) = 48, Projection (in) = 42, Depth (in) = 54 = 3 input(s) provided
- Calculate VolumeVolume78.75 = 78.75
Engine last updated . Checked against 1 independently-derived test — how we verify calculators.
Related Calculators
The questions that sit next to this one — chosen by subject, including calculators filed under a different category.
Masonry
CMU Block Count
Stretcher face area with 5% waste; rough mortar bags.
Structural EngineeringAnchor Embedment
Illustrative tension embedment — verify with ICC-ES data.
Oil & GasWell Spacing Calculator
Calculate optimal well spacing from drainage radius.
Fire SafetyFire Egress Calculator
Calculate exit width, number of exits, and travel distance based on occupant load per IBC.
Construction EstimatingUnit Price Estimator Calculator
Cost per unit from labor, material, equipment, and overhead.
More in Construction & Building Trades.