Skip to main content

Methodology

Part-Time Salary Equivalent methodology

Compare annual pay at two weekly schedules while holding the implied hourly rate constant.
Duc Nguyen X.By Duc Nguyen X.· Founder, Wage101Last reviewed: View update historyMethodology

Educational only: Work and pay decision support, not tax, legal, financial or career advice.

Privacy: Calculations run locally; Wage101 does not receive your work or pay inputs.

Update policy: Reviewed when formulas or official dependencies change.

Scope: Market-neutral work and pay planning using your own assumptions.

1. Formulas and units

Target annual pay
targetPay = sourcePay ÷ sourceHours × targetHours

Where

sourcePay
Current annual pay (currency units/year)Source: Work record
sourceHours
Current weekly hours (hours/week)Source: Work record
targetHours
Target weekly hours (hours/week)Source: User decision
targetPay
Equivalent target annual pay (currency units/year)Source: Calculated output
Implied hourly pay
hourlyPay = sourcePay ÷ (sourceHours × weeksPerYear)

Where

sourcePay
Current annual pay (currency units/year)Source: Work record
sourceHours
Current weekly hours (hours/week)Source: Work record
weeksPerYear
Paid weeks per year (weeks/year)Source: Work record
hourlyPay
Implied hourly pay (currency units/hour)Source: Calculated output
Annual pay difference
payDifference = targetPay − sourcePay

Where

sourcePay
Current annual pay (currency units/year)Source: Work record
payDifference
Annual pay difference (currency units/year)Source: Calculated output
Target hours ratio
hoursRatio = targetHours ÷ sourceHours

Where

sourceHours
Current weekly hours (hours/week)Source: Work record
targetHours
Target weekly hours (hours/week)Source: User decision
hoursRatio
Target hours ratio (share of current hours)Source: Calculated output

Money inputs and outputs use the currency selected in the scenario without changing the canonical methodology. Pay, time, benefits and work-related costs use the units stated beside each input.

2. Worked example

Input assumptions

Current gross annual pay of 60,000 for 30 hours a week, compared with a 40-hour schedule over 52 paid weeks.

Calculation and outputs

Example

Current gross annual pay of 60,000 for 30 hours a week, compared with a 40-hour schedule over 52 paid weeks.

Equivalent target annual pay
80,000.00 currency units
Implied hourly pay
38.46 currency units
Annual pay difference
20,000.00 currency units
Target hours ratio
133.3%

Use the target salary as a gross-pay comparison, then consider taxes, schedule stability and workload separately.

Interpretation

Use target pay as the annual salary that preserves the current implied hourly rate.

3. Validation and boundary checks

  • When target and current hours match, equivalent pay matches current pay.
  • Doubling target hours doubles equivalent annual pay.
  • Zero or out-of-range pay and hours return an input error.

4. Assumptions and source classification

  • Both schedules use the same number of paid weeks.
  • The implied hourly rate stays unchanged.
  • Pay is gross and excludes benefits, tax and overtime premiums.

This calculator has no current policy-data dependency. Its work and pay assumptions are user supplied. Registered family-level regression suites exercise the shared work-logic engine and worked-result reconciliation.

5. Limitations

  • This is a like-for-like time conversion, not a market salary benchmark.
  • Benefits and paid leave may not scale directly with hours.
  • The result cannot determine whether an offer is fair or compliant.

This is educational decision support, not personalised tax, legal, financial or career advice. Check the treatment of your circumstances under the rules that apply to you 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. There is no official threshold or benchmark to refresh for this calculator. Work and pay inputs remain user-supplied because they vary by person, job and contract.

Change history

  1. : Initial public release of the Part-Time Salary Equivalent planner and methodology.

Related reading

Use these practical guides to interpret the decision and its assumptions.

Return to the calculator