Support ratio

What is a support ratio?

A support ratio is the number of support workers compared with the number of participants sharing that support, written workers:participants. 1:1 means one worker supports one person, 1:3 means one worker is shared by three people, and 2:1 means two workers support one person at the same time. Ratios decide how much of a worker's time each participant is funded and charged for.

The term is used most in Supported Independent Living (SIL), where the NDIA's SIL operational guideline defines a ratio of support as "how many disability support workers will provide your support, and how many participants you'll share this support with". It also comes up in group programs, community access and therapy groups, wherever one worker supports more than one person.

When people search for ratios, they usually mean one of these:

• 1:1 support: a dedicated worker for one participant, for example for personal care, community access or a period at home alone.
• Shared support such as 1:2, 1:3 or 1:4: one worker supporting several housemates or group members at once.
• Two-worker support such as 2:1 or 2:3: two workers needed at once, for one person (two-person manual handling) or for a busy routine across a house.

How support ratios work

The arithmetic is the same everywhere: each participant is funded for their share of the staff time. Hours per participant = (number of workers × hours) ÷ number of participants sharing. A one-to-one hour is charged to that participant alone; a shared hour is split.

So a participant at 1:3 for four hours uses about 1.33 hours of their funding, while a participant who needs 2:1 for the same four hours uses 8 hours. That is why the ratio, more than the number of hours, often drives the size of a SIL budget.

Support ratios in SIL

For SIL, the NDIA first works out how many hours of support a participant needs in an ordinary week, then the ratio for those hours. The guideline says it considers what ratio meets the person's disability support needs and the NDIS funding criteria, including value for money, and covers "the times you need more support, and the times you need less support". Its examples include one worker supporting two participants, or two workers supporting four.

Ratios usually change across the day. A house might run 2:4 during morning personal care, 1:1 for one resident at home while the others attend day programs, 1:4 in the afternoon and 2:4 at dinner and showers. Overnight support is set separately: a sleepover where a person needs up to 2 hours of awake support a night, or active overnight support where a worker must be awake.

A roster of care is where these ratios are laid out half-hour by half-hour. The NDIA's roster of care guide (June 2026) asks providers to list every resident, including people who are not NDIS participants, because staffing depends on everyone in the house. Its tool adds up staff for each half hour and highlights a total that isn't a whole number, such as 1.1 workers, which usually means a ratio was entered wrongly for someone. You can lay out shared hours by resident with the free SIL roster of care tool.

Ratio is not the same as intensity

A ratio says how many workers are present; intensity says what kind of support they give. SIL is priced at a standard or higher intensity level, and the NDIA's roster of care guide links higher intensity to frequent help (at least once per shift) to manage behaviours that need intensive positive behaviour support, or help from a worker with high intensity support skills. A participant can be at 1:3 with higher intensity pricing, or 1:1 at standard intensity. Treat them as two separate decisions, each with its own evidence.

What evidence supports a ratio

A ratio has to be justified by the participant's needs, not by how the house is currently staffed. Higher ratios need stronger evidence:

Evidence usually comes from a functional capacity assessment, a behaviour support plan, manual handling or health support plans, and records such as progress notes and incident history showing when support is actually needed. If a participant's needs change, for example they now need two workers for transfers, the ratio may need a plan reassessment.

Ratios in group and community supports

Outside SIL, ratios apply to group-based supports such as group community activities, centre-based programs and group therapy. The NDIA used to publish separate ratio-based support items for these. After a transition that ended on 31 December 2023, those ratio items were removed, and group supports are generally claimed against the standard 1:1 support item with the worker's time divided between the participants in the group. Separate claims may be possible for non-face-to-face time and, for centre-based supports, a centre capital cost. Check the current NDIS pricing arrangements for exactly how to claim a group support before setting up your billing, and look up items in the NDIS price guide.

Support ratios in claims and service agreements

The ratio on the roster, in the service agreement and in the claim should be the same. For SIL, since 1 July 2026 regular SIL is claimed either weekly or hourly, not both (How to claim SIL supports):

• Weekly claiming: a bundled weekly amount. The service agreement still sets out the typical schedule of supports, including ratios, that the weekly amount pays for.
• Hourly claiming: each participant's claim should match their share of the staff time at the ratio actually delivered.

Either way, only one support can be claimed for any period, so time at a day program funded elsewhere is not also SIL. The NDIA does not fund vacancies: if a housemate moves out, the remaining residents' ratio-based costs should not rise to fill the gap (see SIL vacancy).

Common support ratio mistakes

• Claiming the funded ratio while the roster ran fewer staff. If a 2:3 morning ran with one worker, the participants didn't get what was claimed.
• 1:1 without evidence, for example for a resident who is home alone by choice when shared support would meet their needs.
• Leaving a resident out of the calculation, which makes everyone else's share look larger.
• One 24-hour ratio that hides busy periods and makes the roster impossible to check.
• Forgetting the ratio changes when someone is in hospital or away for the weekend.
• Not updating the service agreement when the house's ratio pattern changes.