When you look at the hourly rate on a payslip, it can feel like you know exactly what a worker costs your business. In reality, that figure is only the beginning.

Across Australian worksites, warehouses and factories, many businesses unknowingly underestimate the true cost of their workforce. This results in tight margins that feel inexplicably under pressure, and decisions that don’t always stack up.

The “secret cost” of your workforce is everything that sits quietly in on-costs. These expenses are real, unavoidable, and often overlooked until they start hurting.

What are on-costs, really?

On-costs are the additional expenses you carry on top of an employee’s base wage. They don’t show up in the advertised hourly rate, but they are very much part of what it costs to have someone on your site, driving your vehicle, or working your line.

Some on-costs are mandatory. Others depend on how your business operates. All of them affect your true labour cost.

Ignoring them doesn’t make them disappear; it just means you’re making decisions with incomplete information.

The main on-costs employers face in Australia

Below are the most common on-costs that apply to many Australian employers. Not every business will have all of these, but most will have several.

Superannuation

The Superannuation Guarantee is currently 12% (as at 2026) and applies to ordinary time earnings. This alone adds a significant layer to every hour worked.

Payroll tax

Payroll tax is state-based, with different thresholds and rates depending on where you operate. Once you exceed the threshold, payroll tax can add several percentage points to your wage bill.

This is a cost many growing businesses only “discover” after they’ve already scaled.

Workers’ compensation insurance

Premiums vary widely depending on industry risk, claims history and state scheme. A low-risk office role and a high-risk site role do not cost the same to insure, even if their wages are similar.

Leave entitlements

Permanent employees accrue:

  • Annual leave
  • Personal/carer’s leave
  • Public holidays

These are paid, even when no productive work is being done. Over a year, this can equate to several weeks of paid time not worked, which must be factored into hourly cost calculations.

Of course, this will depend if your workers are full time, part time, casual, or employed through labour hire. Careful workforce planning can allow you to manage entitlements more efficiently.

Overtime, penalties and allowances

Early starts, night shifts, weekends, travel allowances and site allowances can materially change the real hourly rate being paid. These costs are often variable, which makes them easy to underestimate.

Training, licensing and compliance

Inductions, tickets, renewals, medicals, and safety training all cost time and money. Even when training is mandatory, it is still an on-cost you are funding.

Tools, PPE and uniforms

High-visibility clothing, boots, helmets, tools and replacements can add up quickly. This is especially true of work environments with high wear and tear.

Administration and supervision

Payroll processing, rostering, HR administration, performance management and supervision all consume internal resources. These costs rarely sit in one neat line item, but they are very real.

Fair Work obligations and risk exposure (briefly, but importantly)

Employment costs often slip into regulatory territory. Under the Fair Work framework, employers must ensure correct pay rates, entitlements and classifications. Errors can lead to:

  • Back payments
  • Penalties
  • Reputational damage

Even well-intentioned businesses can get this wrong, particularly as awards change and interpretations evolve. Resources from organisations such as the Fair Work Ombudsman are essential reference points, but they don’t remove the underlying cost of compliance.

Managing (or failing to manage) your compliance can factor into your on-cost, and should also be considered when hiring employees.

A simple guide to estimating your true workforce cost

There is no universal on-cost percentage that applies to every business. However, you can build a practical estimate by working through the following steps.

Step 1: Start with the base hourly rate

This is the wage before penalties, super and allowances.

Step 2: Add statutory costs

Include:

  • Superannuation
  • Workers’ compensation (use your actual premium rate)
  • Payroll tax (if applicable in your state and business size)

These figures can usually be found through your accountant, insurer or state revenue office.

Step 3: Factor in paid time not worked

Estimate the cost of:

  • Annual leave
  • Personal leave
  • Public holidays

Spread these across the total working hours in a year to understand their hourly impact.

Step 4: Layer in operational realities

Ask yourself:

  • How often is overtime worked?
  • What allowances are regularly paid?
  • What does training and compliance cost per worker per year?

These will usually be estimates, but informed estimates will get you closer than if you skip this step.

Step 5: Pressure-test the result

Compare your calculated “true hourly cost” against:

  • Labour hire rates
  • Contractor quotes
  • Project margins

This can be a good litmus test of whether your calculations are correct. Labour hire organisations are experts in calculating on costs, and many will happily answer questions or queries if things don’t seem to be lining up.

This matters when weighing up labour options

When labour hire or outsourced workforce solutions look expensive on the surface, it’s often because their pricing already includes many of the on-costs you’re carrying internally (just less visibly).

Once you understand your true workforce cost, comparisons become clearer, decisions become more rational, and margins become easier to protect.

Seeing the full picture

The real cost of a workforce is really only a secret because people don’t stop to calculate it properly. Taking the time to understand your on-costs won’t just help with budgeting. It will improve hiring decisions, clarify pricing, and give you confidence that your labour strategy is built sustainably.

If you want a second set of eyes on your workforce model, organisations such as Frontline Human Resources can help sense-check assumptions and provide context.