4 on 4 off Shift Pattern Pay Calculator

This calculator works out your gross pay for a 4-on-4-off shift pattern. You enter your hourly rate, the number of hours per shift, and how many weeks you work in a year; it returns your annual gross pay, monthly average, and weekly average. It’s built for employees and managers who want a quick, accurate estimate without building a spreadsheet.

Formula

The 4-on-4-off pattern repeats every 8 weeks: you work 4 days, then have 4 days off. Over 8 weeks you work exactly 4 cycles of 4 days, which is 16 shifts. So the average number of shifts per week is 16 ÷ 8 = 2. The formula for annual gross pay is:

Annual pay = hourly rate × hours per shift × (weeks worked × 2)

Where:

• Hourly rate – your gross pay per hour (currency units).
• Hours per shift – the contracted hours you work each on-day (often 12 for a full-time shift).
• Weeks worked – the number of weeks you actually work in a year. In a 4-on-4-off pattern you work 26 weeks per year (because you work half the days), but you may take paid leave or unpaid leave, so adjust this number accordingly. The default 45.5 assumes you take 6.5 weeks of paid leave (i.e., 52 – 6.5 = 45.5 working weeks).

The factor 2 is the average number of shifts per week for a 4-on-4-off pattern.

Worked Example

Using the default values: hourly rate £15.00, 12 hours per shift, and 45.5 weeks worked per year.

Step 1: Calculate shifts per year: 45.5 weeks × 2 shifts/week = 91 shifts.

Step 2: Calculate gross pay per shift: 12 hours × £15.00 = £180.00.

Step 3: Annual gross pay: 91 shifts × £180.00 = £16,380.00.

Step 4: Monthly average: £16,380.00 ÷ 12 = £1,365.00.

Step 5: Weekly average: £16,380.00 ÷ 45.5 = £360.00 (rounded to 2 decimals).

The calculator shows the same results: annual £16,380.00, monthly £1,365.00, weekly £360.00.

How to Use This Calculator

Enter your exact hourly rate (before tax and deductions) and the number of hours you work per on-shift. The weeks worked field is the one most people get wrong: if you have paid annual leave, you still receive pay for those weeks, so include them as “worked” weeks. For example, a full-time 4-on-4-off worker with 5.6 weeks of statutory leave (UK) would use 52 – 5.6 = 46.4 weeks. If you have unpaid leave, subtract those weeks too.

The result is your gross pay – the amount before tax, National Insurance, pension contributions, or any other deductions. Your take-home pay will be lower. Use this figure for budgeting, comparing job offers, or checking your payslip.

Common Mistakes

Mistake 1: Using 52 weeks without adjusting for leave. The 4-on-4-off pattern already means you work 26 weeks a year if you take no leave. If you take paid leave, you still get paid for those weeks, so you should count them as “worked” weeks. If you take unpaid leave, subtract them. The default 45.5 weeks assumes 6.5 weeks of paid leave, which is common for full-time workers.

Mistake 2: Confusing shifts per week with days per week. You work 4 days on, then 4 days off – that’s an average of 3.5 days per week, but only 2 shifts per week because each shift is a full 24-hour day? No – actually each shift is one day (usually 12 hours). Over 8 weeks you work 16 shifts, so 2 shifts per week. Some people mistakenly use 3.5 as the multiplier, which would overestimate pay by 75%.

Mistake 3: Forgetting overtime or shift premiums. If you work extra hours or receive a night/weekend premium, add that to your hourly rate before calculating. This calculator assumes a flat rate.

Limitations

This calculator gives a gross estimate. It does not account for overtime, shift differentials, bonuses, commissions, or deductions. It also assumes your shift pattern is exactly 4-on-4-off with no gaps. If your pattern rotates or includes additional rest days, the average shifts per week may differ – recalculate using your actual number of shifts per year.

For salaried employees, your annual salary is fixed regardless of the pattern; this calculator is for hourly-paid workers.

Frequently Asked Questions

How many weeks do I actually work in a 4-on-4-off pattern? If you take no leave, you work 26 weeks per year (half the days). With paid leave, you still receive pay for those weeks, so use 52 – (paid leave weeks) as your “weeks worked” figure.

What if I work 12-hour shifts? That’s the most common for 4-on-4-off (e.g., in manufacturing or emergency services). Just enter 12 in the hours per shift field. If you work 10-hour shifts, enter 10.

Does this calculator include overtime? No, it only uses your base hourly rate. If you regularly work overtime, add the average overtime pay to your hourly rate or calculate separately.

Is the 4-on-4-off pattern the same as the DuPont schedule? No, the DuPont schedule is a 12-hour rotating pattern over 4 weeks (e.g., 2 days on, 2 off, 3 days on, 2 off, 2 on, 3 off). The 4-on-4-off is simpler: 4 days on, 4 days off, repeating. This calculator is only for the 4-on-4-off pattern.

Can I use this for part-time 4-on-4-off? Yes, if you work fewer hours per shift, just enter that number. The pattern still averages 2 shifts per week, so the formula holds.

Final Thoughts

Knowing your gross pay for a 4-on-4-off pattern helps with budgeting and job comparisons. The key is to get the weeks worked right – include paid leave, exclude unpaid leave. Use this calculator as a quick reference, but always check your actual payslip for exact figures, as employers may calculate leave differently.

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in rate | Hourly rate | £ | 15.00 | 0
in hours | Hours per shift | h | 12 | 0
in weeks | Weeks worked per year | weeks | 45.5 | 0
out annual | Annual gross pay | £ | rate * hours * (weeks * 3.5) | 2
out monthly | Monthly average | £ | annual / 12 | 2
out weekly | Weekly average | £ | annual / weeks | 2