Accessible Parking Calculator
How many accessible parking bays a car park needs from its total spaces and the rate your code applies — with the van-accessible share and the area those bays take.
Codes require a share of spaces to be accessible, with a minimum of one: the IBC uses a sliding scale of about 4% for small lots falling to 2% for large ones; Australian and UK rules use 1–3% depending on the building use, and healthcare and aged care need more.
How the accessible parking calculator works
Codes require a share of spaces to be accessible, with a minimum of one: the IBC uses a sliding scale of about 4% for small lots falling to 2% for large ones; Australian and UK rules use 1–3% depending on the building use, and healthcare and aged care need more. A share of the accessible bays — one in six under the ADA — must be van-accessible with a wider shared zone. Each accessible bay takes about 1.5 standard bays of area.
Formula: accessible = max(minimum, ceil(total × rate)); van = ceil(accessible ÷ 6)
Worked examples
| Inputs | Accessible bays required | Note |
|---|---|---|
| 180 spaces at 2% | 4 | 4 accessible, 1 van |
| A 20-space lot | 1 | 1 — the minimum |
| A hospital lot of 600 at 5% | 30 | 30 accessible, 5 van |
FAQFrequently asked questions
What rate applies to me?
It is set by the building code and the use: shopping and public buildings commonly 2–3%, offices 1–2%, healthcare 4–10%. The IBC table gives absolute counts by lot size rather than a percentage; enter the rate that reproduces it for your size.
What makes a bay van-accessible?
A wider shared zone (2.4 m rather than 1.5) on the passenger side so a lift or ramp can deploy, plus 2.5 m of headroom on the route in. Under the ADA one in every six accessible bays must be van-accessible.
Can two bays share a zone?
Yes — a shared zone between two accessible bays serves both, which is why they are usually laid out in pairs. The area row counts half a bay of extra space per accessible bay for that reason.
Where should they go?
On the shortest accessible route to the entrance, on a level surface, without crossing traffic where possible; distributed across entrances if there are several.
Where these figures come from
- Sabine (1922) — Collected Papers on Acoustics — the reverberation-time equation
- CIBSE Guide A — Environmental design — daylight, comfort and ventilation criteria
- Neufert — Architects' Data — the standard reference for space and dimension
- International Code Council — International Building Code — occupant load and egress factors
- Australian Building Codes Board — National Construction Code — the body that writes Australia's building code
Last checked: September 2026. Formulas are the standard building-science and code relationships; default thresholds are common international values and should be replaced with the ones in your code.