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Methodology

Australia Employee vs Contractor Cost methodology

This methodology explains a bounded commercial cost-and-capacity comparison using entered employee and contractor scenarios. It deliberately refuses to classify the worker or decide obligations.
Duc Nguyen X.By Duc Nguyen X.ยท Founder, Margin101Last reviewed: View update historyMethodology

Educational only: Business decision support, not accounting, tax or legal advice.

Privacy: Calculations run locally; Margin101 does not receive your commercial inputs.

Update policy: Reviewed when formulas or official dependencies change.

Scope: Australian small-business planning using your own assumptions.

1. Formulas and units

Contractor minus employee annual cost
D = C โˆ’ E

Where

E
Employee annual cost (AUD/year)Source: Calculated output
C
Contractor annual cost (AUD/year)Source: Calculated output
D
Contractor minus employee annual cost (AUD/year)Source: Calculated output
Employee annual cost
E = B + S + Oโ‚‘

Where

B
Annual base salary (AUD/year)Source: Business record
Oโ‚‘
Other employee on-costs (AUD/year)Source: Business record
E
Employee annual cost (AUD/year)Source: Calculated output
S
Calculated super contribution (AUD/year)Source: Calculated output
Contractor annual cost
C = r ร— H๊œ€ + O๊œ€

Where

r
Contractor hourly rate excluding GST (AUD/hour)Source: Business record
C
Contractor annual cost (AUD/year)Source: Calculated output
Employee cost per productive hour
Cโ‚‘ = E รท Hโ‚‘

Where

E
Employee annual cost (AUD/year)Source: Calculated output
Hโ‚‘
Employee productive hours (hours/year)Source: Calculated output
Cโ‚‘
Employee cost per productive hour (AUD/hour)Source: Calculated output
Contractor cost per purchased hour
c๊œ€ = C รท H๊œ€

Where

C
Contractor annual cost (AUD/year)Source: Calculated output
Break-even contractor hourly rate
r* = (E โˆ’ O๊œ€) รท H๊œ€

Where

E
Employee annual cost (AUD/year)Source: Calculated output
r*
Break-even contractor hourly rate (AUD/hour)Source: Calculated output
Employee productive hours per person
Hโ‚‘ = (W โˆ’ L) ร— (h โˆ’ n)

Where

W
Paid weeks (weeks/year)Source: User assumption
L
Leave weeks (weeks/year)Source: Reviewed official rule ยท Annual leave planning weeks
h
Ordinary weekly hours (hours/week)Source: Reviewed official rule ยท Award-free ordinary weekly hours
n
Non-productive weekly hours (hours/week)Source: User assumption
Hโ‚‘
Employee productive hours (hours/year)Source: Calculated output
Contractor minus employee hours per person
ฮ”H = H๊œ€ โˆ’ Hโ‚‘

Where

Hโ‚‘
Employee productive hours (hours/year)Source: Calculated output
ฮ”H
Contractor minus employee productive hours (hours/year)Source: Calculated output
Selected workforce headcount
N = Nโ‚‘ + N๊œ€

Where

Nโ‚‘
Employee headcount (whole people)Source: User assumption
N
Selected workforce headcount (people)Source: Calculated output
Selected workforce productive capacity
Hโ‚˜ = Nโ‚‘ ร— Hโ‚‘ + N๊œ€ ร— H๊œ€

Where

Hโ‚‘
Employee productive hours (hours/year)Source: Calculated output
Nโ‚‘
Employee headcount (whole people)Source: User assumption
Hโ‚˜
Selected workforce productive capacity (hours/year)Source: Calculated output
N
Selected workforce headcount (people)Source: Calculated output
Selected workforce annual cost
Cโ‚˜ = Nโ‚‘ ร— E + N๊œ€ ร— C

Where

E
Employee annual cost (AUD/year)Source: Calculated output
C
Contractor annual cost (AUD/year)Source: Calculated output
Nโ‚‘
Employee headcount (whole people)Source: User assumption
N
Selected workforce headcount (people)Source: Calculated output
Cโ‚˜
Selected workforce annual cost (AUD/year)Source: Calculated output
Workforce cost per productive hour
Cโ‚˜โ‚• = Cโ‚˜ รท Hโ‚˜

Where

Hโ‚˜
Selected workforce productive capacity (hours/year)Source: Calculated output
Cโ‚˜
Selected workforce annual cost (AUD/year)Source: Calculated output
Cโ‚˜โ‚•
Workforce cost per productive hour (AUD/hour)Source: Calculated output
Demand capacity gap
Gโ‚• = max(0, Hแตฃ โˆ’ Hโ‚˜)

Where

Hโ‚˜
Selected workforce productive capacity (hours/year)Source: Calculated output
Hแตฃ
Required productive-hour demand (hours/year)Source: User assumption
Gโ‚•
Demand capacity gap (hours/year)Source: Calculated output
max
Maximum operator (operator)Source: Calculated output
Overtime cost for the capacity gap
Cโ‚’ = Gโ‚• ร— Cโ‚‘ ร— mโ‚’

Where

Gโ‚•
Demand capacity gap (hours/year)Source: Calculated output
mโ‚’
Overtime cost multiplier (multiplier)Source: User assumption
Cโ‚‘
Employee cost per productive hour (AUD/hour)Source: Calculated output
Cโ‚’
Overtime cost for the capacity gap (AUD/year)Source: Calculated output
Whole hires required for the capacity gap
Nโ‚• = ceil(Gโ‚• รท Hโ‚‘)

Where

Hโ‚‘
Employee productive hours (hours/year)Source: Calculated output
Gโ‚•
Demand capacity gap (hours/year)Source: Calculated output
Nโ‚•
Whole hires required to cover the gap (whole people)Source: Calculated output
Whole-hire cash cost for the capacity gap
Cโ‚• = Nโ‚• ร— (Fโ‚• + E)

Where

E
Employee annual cost (AUD/year)Source: Calculated output
Fโ‚•
New-hire fixed cost per employee (AUD/hire)Source: User assumption
Nโ‚•
Whole hires required to cover the gap (whole people)Source: Calculated output
Cโ‚•
Hire cost for the capacity gap (AUD/year)Source: Calculated output
Lower-cost capacity-gap option
O* = min(Cโ‚’, Cโ‚•)

Where

Cโ‚’
Overtime cost for the capacity gap (AUD/year)Source: Calculated output
Cโ‚•
Hire cost for the capacity gap (AUD/year)Source: Calculated output
O*
Lower-cost capacity-gap option (decision state)Source: Calculated output
min
Minimum operator (operator)Source: Calculated output
Overtime-to-hire crossover hours
H* = ceil((Fโ‚• + E) รท (Cโ‚‘ ร— mโ‚’)), when H* โ‰ค Hโ‚‘

Where

E
Employee annual cost (AUD/year)Source: Calculated output
Hโ‚‘
Employee productive hours (hours/year)Source: Calculated output
mโ‚’
Overtime cost multiplier (multiplier)Source: User assumption
Fโ‚•
New-hire fixed cost per employee (AUD/hire)Source: User assumption
Cโ‚‘
Employee cost per productive hour (AUD/hour)Source: Calculated output
H*
Overtime-to-hire crossover hours (hours)Source: Calculated output

Money inputs and outputs use AUD. Rates, margins, utilisation and buffers are entered as percentages and converted to decimal values for calculation.

2. Worked example

Input assumptions

The default fixture uses a $100,000.00 base salary and $95.00 contractor rate for 1,400 purchased hours.

Calculation and outputs

Example

The default fixture uses a $100,000.00 base salary and $95.00 contractor rate for 1,400 purchased hours.

Contractor minus employee annual cost
$15,000.00
Employee annual cost
$120,000.00
Contractor annual cost
$135,000.00
Employee cost per productive hour
$78.13
Contractor cost per purchased hour
$96.43
Break-even contractor hourly rate
$84.29
Employee productive hours per person
1,536 hours
Contractor minus employee hours per person
-136 hours
Selected workforce headcount
3
Selected workforce productive capacity
4,472 hours
Selected workforce annual cost
$375,000.00
Workforce cost per productive hour
$83.86
Demand capacity gap
528 hours
Overtime cost for the capacity gap
$61,875.00
Whole hires required for the capacity gap
1
Whole-hire cash cost for the capacity gap
$128,000.00
Lower-cost capacity-gap option
overtime
Overtime-to-hire crossover hours
1,093 hours

The engine returns employee annual cost of $120,000.00, contractor annual cost of $135,000.00 and a contractor-minus-employee gap of $15,000.00.

Interpretation

Use the result to compare entered commercial capacity and cost scenarios; it does not determine worker status, award coverage or legal obligations.

3. Validation and boundary checks

  • All money and hour inputs must be finite; entered costs and hours cannot be negative.
  • Paid weeks must be greater than zero and at most 53; leave weeks must be below paid weeks.
  • Non-productive weekly hours must be below reviewed ordinary weekly hours.
  • Contractor purchased hours and employee productive hours must remain above zero.
  • Employee annual cost reconciles to salary plus engine-calculated super plus entered on-costs.
  • Contractor annual cost reconciles to rate times purchased hours plus entered additional costs.
  • The engine fails closed until the user confirms this is a commercial comparison, not a classification decision.
  • Employee and contractor headcounts must be whole non-negative numbers; mix capacity and cost reconcile to their per-person engine results.
  • The adult, full-time and award-free national-system scope codes fail closed outside the bounded reviewed fixture.
  • Overtime multiplier must be at least one; required hires are rounded up to enough whole employees to cover the capacity gap.

4. Assumptions and source classification

  • The exact reviewed policy version is ato-super-guarantee-rate-au@2026-07-13;fair-work-annual-leave-au@2026-07-13;fair-work-ordinary-hours-au@2026-07-13.
  • The entered employee and contractor scenarios cover the same decision period and use a consistent GST basis.
  • Every applicable cost omitted from the defaults is entered by the user.
  • Purchased and productive hours are capacity measures; they do not assert equal output or quality.
  • The supported defaults are an award-free starting scenario, not a conclusion about the actual arrangement.
  • Required productive hours are a user-owned demand record; the tool does not forecast demand.

Official dependencies used by this comparison calculator are captured in the Margin101 evidence register and version-acknowledged in this page history. User-entered commercial assumptions remain separate from those official inputs.

5. Limitations

  • This is not a worker-classification, employment, superannuation, award, payroll-tax, withholding, insurance, work-health-and-safety, tax or legal determination.
  • The tool does not model all awards, enterprise agreements, leave categories, penalty rates, overtime, payroll-tax thresholds, insurance policies or engagement terms.
  • The tool does not value continuity, control, equipment, intellectual property, substitution, quality, delivery risk or demand flexibility.
  • The overtime-versus-hire comparison does not model award-specific overtime rules, recruitment probability, ramp-up, attrition or staged hiring dates.
  • Use the relevant authority guidance and qualified advisers for the actual arrangement.

This is educational decision support, not tax, accounting, legal or financial advice. Check the treatment of your actual transactions under the rules that apply in Australia and seek qualified advice where appropriate.

6. Update and evidence policy

Registered family-level suites test formula invariants and example reconciliation; the release ledger records that coverage without claiming a separate oracle for every line of public copy. Registered official sources block dependent public workflows when their evidence or version acknowledgement is unavailable or invalid. Commercial inputs remain user-supplied because they vary by business and contract.

Change history

  1. : Initial public release of the planner and methodology after pre-launch calculation, content, source and interaction review.

Related reading

Guides to interpret the decision and its assumptions.

Return to the comparison calculator