Wheelchair Restraint Calculator for WTORS Shoulder-Belt Geometry
The Estraints Wheelchair Restraint Calculator helps wheelchair accessible vehicle modifiers, engineers, installers and compliance teams calculate and document upper shoulder-belt anchorage geometry for a wheelchair-seated occupant.
The calculation uses the selected standards framework together with occupant, wheelchair and vehicle measurements. It provides a repeatable technical record rather than relying on visual judgement alone.
Start a WTORS Calculation See How the Calculator Works
What problem does the wheelchair restraint calculator solve?
Installing compliant restraint hardware does not automatically mean the shoulder-belt path will be appropriate for every wheelchair passenger. Occupant size, wheelchair seating height, wheelchair position and vehicle anchorage location all affect the resulting geometry.
Estraints provides a consistent process for entering the relevant measurements, assessing the geometry and generating a report that can be retained with the vehicle or project file.
Who is the calculator for?
- Wheelchair accessible vehicle manufacturers and modifiers
- Mobility equipment installers
- Vehicle engineers and certifiers
- OEM and body engineering teams
- Fleet and quality-assurance teams
- Organisations standardising repeat WAV builds
What does an Estraints report provide?
- Calculated upper shoulder-belt anchorage coordinates
- Standards-based geometry assessment for the selected framework
- Graphical views of the assessed geometry
- A record of the relevant vehicle, wheelchair and occupant inputs
- Downloadable documentation for engineering and QA records
Why calculate instead of positioning the belt by eye?
A location that appears suitable for one passenger may create a different belt path for another wheelchair or occupant size. A calculation-based method makes the decision easier to repeat, review and document.
Which wheelchair transportation standards can be considered?
The responsible professional still needs to select the correct current standard and satisfy the applicable vehicle and regulatory requirements. Estraints supports calculation and documentation; it does not certify the vehicle.
How does the Estraints calculator work?
- Select the relevant standards framework.
- Enter the vehicle, wheelchair and occupant information.
- Enter the required measurements.
- Generate the calculated anchorage result.
- Review the graphical output.
- Save or download the report for the project record.
Frequently asked questions
What is a wheelchair restraint calculator?
A wheelchair restraint calculator is a technical tool used to assess restraint geometry for a wheelchair-seated occupant. Estraints focuses on upper shoulder-belt anchorage geometry using the selected standards framework and measured vehicle/occupant inputs.
What shoulder-belt angle should I use for a wheelchair passenger?
Do not apply one universal angle to every installation. The acceptable geometry depends on the applicable standard and the measured relationship between the occupant, wheelchair position and upper anchorage. Estraints uses the selected standards framework to calculate and document that relationship.
Does the calculator certify my vehicle?
No. It supports calculation and documentation. Structural integrity, installation, regulatory compliance and certification remain separate responsibilities.
Can the same upper anchorage position be used for every wheelchair passenger?
Not automatically. Different occupant sizes, wheelchair heights and wheelchair positions can change the resulting belt path.
Does Estraints replace the standard?
No. Users should have access to the applicable current standard and relevant manufacturer instructions.
Calculate the Shoulder-Belt Anchorage Position
Content status: Updated by the Estraints Technical Team on 24 September 2026. See how Estraints develops and reviews technical guidance.