Effective Clear Opening Width Calculator

Our interactive Effective Clear Opening Width Calculator below allows you to work out the Clear Opening Width, Leaf Width, Frame Width or Structural Opening Width for a number of varied door constructions.

To use the calculator, click on Filter 1 for the Known Dimensions, Filter 2 for the Leaf Configuration, and Filter 3 for the Leaf Action for the required construction. Default dimensions are provided and can be amended by typing in the required data. Results will be calculated automatically.

Please note, the actual door leaf width required to ensure the correct ‘Effective Clear Width’ as identified in Approved Document M and BS8300-2: 2018, will depend on the combination of several variables for reference:

Leaf thickness
Rebate/stop depth
Hinge knuckle diameter
Ironmongery projection (e.g. lever handles)

Single Leaf - Single Action	Dimensions in mm
Structural Opening Width
Frame To Wall Gap
Frame Width
Hinge Jamb Frame Thickness
Non Hinge Frame Jamb Thickness
Hinge Knuckle Diameter
Leaf Thickness
Rebate/Stop Depth
Leaf To Frame Gaps
Leaf Width
Ironmongery Projection
Clear Opening Width

Single Leaf - Double Action	Dimensions in mm
Structural Opening Width
Frame To Wall Gap
Frame Width
Hinge/Pivot Jamb Frame Thickness
Non Hinge/Pivot Frame Jamb Thickness
Pivot Point To Jamb
Leaf Thickness
Rebate/Stop Depth
Leaf To Frame Gaps
Leaf Width
Ironmongery Projection
Clear Opening Width

Single Leaf - AhmGuard Action	Dimensions in mm
Structural Opening Width
Frame To Wall Gap
Frame Width
Hinge/Pivot Jamb Frame Thickness
Non Hinge/Pivot Frame Jamb Thickness
Pivot Point To Jamb
Leaf Thickness
Rebate/Stop Depth
Leaf To Frame Gaps
Leaf Width
Ironmongery Projection
Clear Opening Width

Equal Leaf Pair - Single Action	Dimensions in mm
Structural Opening Width
Frame To Wall Gap
Frame Width
Hinge Jamb Frame Thickness
Non Hinge Frame Jamb Thickness
Hinge Knuckle Diameter
Leaf Thickness
Leaf To Frame Gaps
Primary Leaf Width
Secondary Leaf Width
Meeting Stile Tolerance
Ironmongery Projection
Clear Opening Width

Equal Leaf Pair - Double Action	Dimensions in mm
Structural Opening Width
Frame To Wall Gap
Frame Width
Hinge/Pivot Jamb Frame Thickness
Non Hinge/Pivot Frame Jamb Thickness
Pivot Point To Jamb
Leaf Thickness
Leaf To Frame Gaps
Primary Leaf Width
Secondary Leaf Width
Meeting Stile Tolerance
Ironmongery Projection
Clear Opening Width

Equal Leaf Pair - AhmGuard Action	Dimensions in mm
Structural Opening Width
Frame To Wall Gap
Frame Width
Hinge/Pivot Jamb Frame Thickness
Non Hinge/Pivot Frame Jamb Thickness
Pivot Point To Jamb
Leaf Thickness
Leaf To Frame Gaps
Primary Leaf Width
Secondary Leaf Width
Meeting Stile Tolerance
Ironmongery Projection
Clear Opening Width

Unequal Leaf Pair - Single Action	Dimensions in mm
Structural Opening Width
Frame To Wall Gap
Frame Width
Hinge Jamb Frame Thickness
Non Hinge Frame Jamb Thickness
Hinge Knuckle Diameter
Leaf Thickness
Leaf To Frame Gaps
Primary Leaf Width
Secondary Leaf Width
Meeting Stile Tolerance
Ironmongery Projection
Clear Opening Width

Unequal Leaf Pair - Double Action	Dimensions in mm
Structural Opening Width
Frame To Wall Gap
Frame Width
Hinge/Pivot Jamb Frame Thickness
Non Hinge/Pivot Frame Jamb Thickness
Pivot Point To Jamb
Leaf Thickness
Leaf To Frame Gaps
Primary Leaf Width
Secondary Leaf Width
Meeting Stile Tolerance
Ironmongery Projection
Clear Opening Width

Unequal Leaf Pair - AhmGuard Action	Dimensions in mm
Structural Opening Width
Frame To Wall Gap
Frame Width
Hinge/Pivot Jamb Frame Thickness
Non Hinge/Pivot Frame Jamb Thickness
Pivot Point To Jamb
Leaf Thickness
Leaf To Frame Gaps
Primary Leaf Width
Secondary Leaf Width
Meeting Stile Tolerance
Ironmongery Projection
Clear Opening Width

Fire Doors Manufactured by Ahmarra for Bournemouth & Poole College’s Lansdowne Campus

Latest Project

Fire Doors Manufactured by Ahmarra for Bournemouth & Poole College’s Lansdowne Campus

Ahmarra were proud to manufacture over 250 Q-Mark certified fire doorsets, non-fire doorsets and glazed screens for Bournemouth & Poole College’s new purpose-built four-storey teaching facility within its Lansdowne campus.

Navigating the Transition from BS 476 Part 22 to BS EN 1634-1: What It Means for Fire Door Specification

In 2024, the UK Government confirmed that the BS 476 National Classification standards will be withdrawn from Approved Document B (England) in favour of BS EN 13501. A five-year transition period means that fire-resistant products such as doorsets will need to be classified to EN 13501-2 by 2nd September 2029. At Ahmarra, we’re working closely with our component suppliers and systems houses to complete the required fire testing to BS EN 1634-1.

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From our initial visit to the factory through to pricing, production, delivery and after care, I couldn’t recommend this company highly enough. Look no further, this company is first class.

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