How to use the Door Frame Cubic Feet Calculator
- Measure the outer frame width and height, opening width and height, and uniform front-to-back depth.
- Enter the outer rectangle, inner opening and uniform frame depth for the complete four-sided model.
- Select Calculate. Review the result and its working; if you change an input, calculate again before copying or sharing.
Door Frame formula
Subtract opening area from outer area, then multiply by uniform depth. This describes a complete four-sided rectangular ring.
Frame volume = (outer width × outer height − opening width × opening height) × depth × quantity
What the terms mean
- Outer frame width
- A measured length in the selected unit; it is converted to feet before volume is calculated.
- Outer frame height
- A measured length in the selected unit; it is converted to feet before volume is calculated.
- Opening width
- A measured length in the selected unit; it is converted to feet before volume is calculated.
- Opening height
- A measured length in the selected unit; it is converted to feet before volume is calculated.
- Frame depth
- A measured length in the selected unit; it is converted to feet before volume is calculated.
- Number of identical items
- The whole-number count of objects with the same entered dimensions.
Door Frame worked examples
Measure material in a complete four-sided frame
The outer rectangle is 3.5 ft × 7.5 ft and the opening is 3 ft × 7 ft. The frame is uniformly 4 in deep and includes all four sides.
- (Outer width × outer height − opening width × opening height) × depth × quantity
Answer: 1.75 ft³. Cubic yards: 0.064815 yd³; Litres: 49.554482 L.
Measure a deeper four-sided frame
The outer rectangle is 4 ft × 8 ft, the opening is 3.5 ft × 7.5 ft, and the depth is 6 in. Assume a complete, solid rectangular ring.
- (Outer width × outer height − opening width × opening height) × depth × quantity
Answer: 2.875 ft³. Cubic yards: 0.106481 yd³; Litres: 81.410934 L.
Door Frame Cubic Feet Calculator FAQs
Does this include the empty door opening?
No. The opening area is subtracted before multiplying by frame depth.
Can I use it for a three-sided jamb?
Use the wood calculator for the two legs and top member separately. This page assumes a complete four-sided rectangular frame.
Measurement guide for Door Frame
This model measures a complete four-sided rectangular ring. A three-sided doorway needs its individual jambs and header measured separately.
Assumptions and limits
This model includes all four sides. Many door jambs have only three sides or decorative profiles; measure those as separate pieces in the wood calculator.
A complete rectangular frame with uniform depth. Decorative profiles and three-sided jambs need separate component measurements.
Check your result
Check that both opening dimensions are smaller than the outer rectangle. The result describes the material in a complete ring, not the air in the doorway.