How to Calculate Ramp Gradient 

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If you’re calculating a ramp gradient in Australia, you’re already taking an important step toward safer and more accessible entry to a home or commercial building. Ramp slope affects usability, safety, compliance and long-term practicality — especially for wheelchair users and individuals relying on mobility aids.

This guide explains how to calculate ramp gradient correctly under commonly referenced Australian access standards and what that means for real-world home modification projects.

What is Ramp Gradient?

Ramp gradient describes how steep a ramp is. It is calculated as the vertical rise divided by the horizontal run.

• Ratio format: 1:14
• Percentage format: 7.14%

A 1:14 gradient means that for every 1 metre of vertical rise, the ramp must extend at least 14 metres horizontally.

For users accessing homes with electric wheelchairs or mobility scooters, proper ramp gradient is essential for safe independent access.

Wheelchair Ramp Gradient Under Australian Standards

Accessible wheelchair ramp gradient in Australia commonly references AS 1428.1 – Design for access and mobility, which is linked within the National Construction Code (NCC) for certain building classifications.

Relevant legislation and guidance include:

• Disability (Access to Premises — Buildings) Standards 2010
• National Construction Code (NCC)
• AS 1428.1 – Design for Access and Mobility

A commonly referenced maximum ramp gradient for accessible ramps is:

1:14 (≈7.14%)

Gentler gradients such as 1:20 (5%) are often preferred in home modification settings where space allows, as they reduce fatigue and improve safety for independent users using folding electric wheelchairs or walking aids.

The ramp angle for wheelchair use converts to degrees as follows:

• 1:20 gradient = 2.9° — gentlest, recommended where space allows
• 1:14 gradient = 4.1° — standard maximum under AS 1428.1
• 1:8 gradient = 7.1° — steeper, only suitable for very short rises

Converting gradient to degrees helps when comparing ramp specifications or interpreting supplier documentation.

How to Calculate Ramp Gradient

To calculate ramp slope, measure:

• Rise: the vertical height difference
• Run: the horizontal length available

Formula:

Gradient (%) = (Rise ÷ Run) × 100

Example: If the rise is 150mm (0.15m) and you design at 1:14:

Run = 0.15 × 14 = 2.1 metres

Gradient = (0.15 ÷ 2.1) × 100 ≈ 7.14%

Quick 1:14 Ramp Length Calculator

Not sure which ramp length you need? Contact our team with your rise measurement and we’ll recommend the right solution.

Why Gradient Matters in Home Modifications

In NDIS home modification projects, ramp design must balance compliance with everyday usability. A ramp that is technically compliant but too steep for independent use may still be impractical.

• Turning space at entries
• Landing platforms
• Surface slip resistance
• Handrails where required
• Drainage considerations
• Integration with existing pathways

Proper ramp planning is especially important for users relying on bariatric wheelchairs, mobility scooters and powered mobility devices where additional space and turning clearance may be required.

This is where certified building oversight and engineering review become critical in achieving safe, durable outcomes.

For properties with raised access points or difficult vehicle transfers, many households also combine ramps with wheelchair lifts or boot hoist and wheelchair transport solutions.

Types of Wheelchair Ramps Available in Australia

Once you know your required gradient and ramp length, choosing the right ramp type depends on whether the installation is permanent, semi-permanent or portable.

Threshold ramps — low-profile aluminium ramps for doorways, sliding doors and small height differences. Ideal for rises under 80mm. From $90.

Portable wheelchair ramps — lightweight folding aluminium ramps for steps, vehicles and temporary access. Suitable for rises up to 300mm depending on length. From $244.

Modular aluminium ramps — rolling and configurable ramp systems for larger rises and permanent home installations. Up to 500kg capacity. Suitable for electric wheelchairs and heavy mobility equipment.

Custom engineered ramps — designed and installed for specific site conditions, entry configurations and NDIS home modification requirements.

For portable ramps for steps, our folding aluminium range can be set up without tools and stored when not in use — ideal for rental properties or multi-location access needs.

NDIS Home Modification Ramp Planning

For NDIS participants, ramp design must align with occupational therapist recommendations, site constraints and long-term mobility needs.

If you are planning a disability ramp for home, our team can assess your property and recommend practical, compliant solutions — including NDIS quote documentation if required.

Many participants also require access solutions compatible with electric wheelchairs, mobility scooters and vehicle transport systems.

Common Ramp Gradient Questions

• What is the safest ramp gradient for wheelchairs?
  A 1:14 gradient (4.1°) is the commonly referenced maximum under AS 1428.1. A 1:20 gradient (2.9°) is safer and gentler where space allows.
• What is the maximum ramp slope for walking in Australia?
  For pedestrian ramps in commercial settings, 1:14 is the typical maximum. For home access ramps, 1:20 is often preferred for elderly users and power mobility devices.
• Can I build a steeper ramp?
  Steeper ramps may be used in limited space situations but can reduce usability and safety, particularly for independent wheelchair or scooter users.
• Does NDIS cover ramp installation?
  NDIS may fund ramps where they are considered reasonable and necessary for safe home access. Gilani Engineering is a registered NDIS provider and can assist with quotes and documentation.
• What is the Australian standard ramp gradient?
  AS 1428.1 commonly references 1:14 as the maximum gradient for accessible ramps in Australia.
• How do I choose the right ramp length?
  Use the calculator above — divide your rise (in mm) by 14 to get the minimum run at 1:14 gradient, or divide by 20 for a gentler 1:20 slope. Our team can also assist with a free site assessment.

Conclusion

Accurate ramp gradient calculations are essential for safe and practical access solutions. By understanding slope requirements and working with experienced professionals, you can ensure your ramp is both compliant and suitable for everyday use.

Whether you need a simple portable aluminium ramp for steps, a permanent disability ramp for home, or a full NDIS-funded home modification, Gilani Engineering supplies and installs ramp solutions across Australia.

For broader access needs, explore our range of folding electric wheelchairs, mobility scooters, wheelchair lifts and NDIS home modifications.

For wheelchair ramp vehicle access, see our boot hoists and vehicle access solutions.