---
title: "How PayByRoster Works — Calculation Engine & Technical Documentation | PayByRoster"
url: https://paybyroster.com/calculator-info
description: "Complete technical documentation for PayByRoster — ATO tax rates, penalty rate calculations, superannuation, Medicare Levy, and how the roster pay calculator works."
lang: en
---

# PayByRoster Calculator Info

Complete technical documentation for PayByRoster — the free pay calculator for Australian roster-based workers.

## What is PayByRoster?

PayByRoster is a free online pay calculator for Australian roster-based workers including FIFO mining, healthcare, emergency services, aviation, maritime, and manufacturing workers. It accurately calculates take-home pay, tax deductions, Medicare Levy, and superannuation contributions for any roster pattern.

## Calculation Engine

### How Calculations Work

PayByRoster uses the latest Australian Taxation Office (ATO) rates for 2025-26:

#### Tax Calculations

| Taxable Income | Tax Rate | Tax Payable |
| --- | --- | --- |
| $0 – $18,200 | 0% | Nil |
| $18,201 – $45,000 | 16% | 16c for each $1 over $18,200 |
| $45,001 – $135,000 | 30% | $4,288 plus 30c for each $1 over $45,000 |
| $135,001 – $190,000 | 37% | $31,288 plus 37c for each $1 over $135,000 |
| $190,001+ | 45% | $51,638 plus 45c for each $1 over $190,000 |

- **Medicare Levy:** 2% of taxable income
- **Medicare Levy Surcharge:** 1.0-1.5% for high earners without private health insurance
- **Low Income Tax Offset (LITO):** Up to $700 (phases out at $66,667)
- **Tax-free threshold:** $18,200 for Australian residents

#### Superannuation

- **Superannuation Guarantee:** 12% of ordinary time earnings (2025-26)
- **Maximum contribution base:** $62,500 per quarter ($250,000 per year)

#### Roster Calculations

- Calculates days worked vs days off per year
- Includes shift penalties, night shift loadings, and weekend rates
- Accounts for public holiday rates
- Calculates total take-home pay after tax and super

### Penalty Rate Calculations

| Penalty Type | Default Rate | Notes |
| --- | --- | --- |
| Night shift | 15-30% | Varies by industry award |
| Saturday | 50-100% | Award-dependent |
| Sunday | 75-200% | Award-dependent |
| Public holidays | 150-250% | Award-dependent |
| Overtime | 150-200% | Time-and-a-half or double-time |

### Stacking Order

Penalties are calculated in the following order:

1. Base hourly rate
2. Shift loading (if applicable)
3. Weekend penalty (if applicable)
4. Public holiday penalty (if applicable)
5. Overtime multiplier (if applicable)

Stacking rules vary by award. PayByRoster uses standard Fair Work stacking unless a custom award is specified.

## Supported Roster Types

### Pre-configured FIFO/DIDO Patterns

| Pattern | Days On | Days Off | Cycle Length |
| --- | --- | --- | --- |
| 2/1 | 14 | 7 | 21 days |
| 7/7 | 7 | 7 | 14 days |
| 8/6 | 8 | 6 | 14 days |
| 4/3 | 4 | 3 | 7 days |
| 2/2 | 14 | 14 | 28 days |
| 14/14 | 14 | 14 | 28 days |
| 21/7 | 21 | 7 | 28 days |
| 28/14 | 28 | 14 | 42 days |
| 4/1 | 28 | 7 | 35 days |

### Healthcare Shift Patterns

- 12-hour shifts (days/nights)
- 8-hour shifts (3 shifts per day)
- 10-hour shifts
- Rotating shift patterns
- Fixed night shift
- On-call arrangements

### Emergency Services

- 10/14 rotating roster
- 24-hour shifts
- Day/Night rotation patterns

### Custom Roster Builder

Users can create custom roster patterns by specifying:

- Days worked per cycle
- Days off per cycle
- Shift length (hours)
- Start/end times
- Rotation frequency

## Features

### Comparison Tool

- Compare up to 3 rosters side-by-side
- See annual days at work vs days off
- Calculate total take-home pay difference
- Factor in work-life balance metrics

### Take-Home Pay Calculator

- Gross salary input
- Automatic tax calculation (2025-26 rates)
- Medicare Levy calculation
- Superannuation deduction (12%)
- Net pay output

### Export Capabilities

**Currently available:**

- Results displayed on screen
- Printable summary

## Accuracy & Compliance

### ATO Compliance

- Tax rates updated annually from official ATO schedules
- Medicare Levy calculations match ATO specifications
- Tax-free threshold and offsets verified against ATO guidelines
- **Last updated:** January 2026 for 2025-26 financial year

### Superannuation

- Superannuation Guarantee rate: 12% (correct as of 1 July 2025)
- Maximum contribution base: $250,000/year (2025-26)
- Calculations align with ATO super guarantee requirements

### Limitations & Disclaimers

- PayByRoster provides estimates for comparison purposes
- Does not replace professional tax advice
- Award interpretations may vary — consult your award or HR department
- Users should verify calculations with their employer or accountant
- Not certified for payroll system integration (Pro API will be audited)

### Testing

- Calculations spot-checked against ATO tax calculator
- Verified with real FIFO worker payslips (sample: 50+ workers)
- Regular updates when tax rates change

## Integrations

### Current Integrations

None (standalone calculator)

## Frequently Asked Questions

### How does PayByRoster calculate penalty rates?

### What fields are in the Excel export?

### How do I upgrade to Pro?

### Can I export my calculations?

### Is my data private?

### How accurate are the calculations?

### What roster types are supported?

### Does it handle shift allowances?

### Can I save my roster comparisons?

### Is PayByRoster mobile-friendly?

## Technical Specifications

### Browser Support

| Browser | Version | Status |
| --- | --- | --- |
| Chrome | 90+ | |
| Firefox | 88+ | |
| Safari | 14+ | |
| Edge | 90+ | |
| Mobile browsers | — | |

### Technology Stack

- **Frontend:** React (via Lovable)
- **Backend:** n8n workflows
- **Database:** Supabase
- **Hosting:** Lovable + edge functions

### Performance

- **Page load:** <2 seconds
- **Calculation time:** <1 second
- **Uptime:** 99.9% target

### Security

- HTTPS encryption
- No personal data stored
- Secure calculation endpoints
- Regular security audits

## Support & Contact

**Website:** https://paybyroster.com/

**Support Email:** paybyroster@outlook.com

**Region:** Australia

**Target Audience:** Australian roster-based workers

**Response time:** 24-48 hours for email inquiries

**Community:** Educational shorts on roster comparisons coming to YouTube.

## Updates & Changelog

### January 2026

- Updated tax rates for 2025-26 financial year
- Superannuation increased to 12%
- Removed LMITO (ended June 2024)
- Added emergency services roster patterns
- Mobile responsiveness improvements

### Planned Q2 2026

- Pro tier launch
- Excel/CSV/PDF export
- Save favourite rosters
- API access

**Last updated:** January 30, 2026

**Tax year:** 2025-26 (1 July 2025 – 30 June 2026)

**Super rate:** 12%

**Source:** Australian Taxation Office, Fair Work Commission

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