4 on 4 Off Shift Pattern: Hours, Pay and Rules for Engineers

A 4 on 4 off shift pattern means you work four shifts in a row, usually 12 hours each, then have four days off. Averaged out that is 42 hours a week and about 182 shifts a year. The maths is simple, the UK working-time rules are less obvious, and this guide covers both. It is not legal advice.

Checked 28 October 2026. The legal points come from GOV.UK pages on night working, weekly hours and rest breaks, and from the HSE guide HSG256, all opened on that date. The arithmetic is our own and is shown so you can check it. Check your contract and Acas for your own case.

What is a 4 on 4 off shift pattern?

It is a rotating pattern where each person works four shifts then has four days off, and the cycle repeats. It lets a site run 24 hours a day, seven days a week with four teams. Two common versions turn up in adverts, and they are different rotas:

• The 8-day version (often written 2 days, 2 nights, 4 off): two day shifts, two night shifts, then four days off. You are on nights for two shifts at a time.
• The 16-day version (4 days, 4 off, 4 nights, 4 off): four day shifts, four days off, four night shifts, four days off. You are on nights for four shifts in a row.

Some vendor pages describe one and some the other, which is why websites seem to disagree. An advert that says only "4 on 4 off, days and nights" does not tell you which, so ask. A "days only 4 on 4 off" job (for example 6am to 6pm) skips the nights.

Here is the 8-day version for four teams over one cycle. D is a day shift, N a night shift, a dash is a day off.

Read down any column and there is exactly one team on days and one on nights, so the site is covered all day. We checked each of the eight columns by hand: day 1 has A on days and D on nights; day 3 has B on days and A on nights; day 5 has C on days and B on nights; day 7 has D on days and C on nights, and so on.

How many hours and shifts a year is that, worked out?

Take the 8-day cycle with 12-hour shifts.

1. Shifts in a cycle: 2 + 2 = 4 shifts of 12 hours, so 4 x 12 = 48 hours in 8 days.
2. Per week: 48 / 8 = 6 hours a day on average, and 6 x 7 = 42 hours a week.
3. Cycles in a year: 365 / 8 = 45.625.
4. Shifts a year: 45.625 x 4 = 182.5, so about 182 or 183 shifts.
5. Hours a year: 182.5 x 12 = 2,190 hours, which is 42 hours x 52.14 weeks.

The 16-day version gives the same totals: 8 shifts x 12 = 96 hours in 16 days, 96 / 16 x 7 = 42 hours a week, and 365 / 16 x 8 = 182.5 shifts. So websites that quote 182 working days a year and a 42-hour average week are consistent with this; any that give a very different figure are describing a different pattern, or counting bank holidays or paid breaks differently. Your contract may count paid breaks and handover time differently, so the hours you are paid for can differ from the hours on site.

A note on pay arithmetic. As an illustration only, and not an advert: a salary of £40,000 for 2,190 hours a year works out at about £18.26 an hour (40,000 / 2,190). Divide any advertised salary by 2,190 to compare it with a day job of 37.5 hours (1,950 hours a year).

What does the law say? Hours, night work and rest

Not legal advice. These are summaries of GOV.UK pages as they read on 28 October 2026. Your contract, any workforce agreement and Acas will tell you what applies to you.

The 48-hour average. GOV.UK says "You cannot work more than 48 hours a week on average", normally measured over 17 weeks, and you can choose to opt out. A 42-hour average sits under that without opting out. Regular overtime pushes the average up, and the page lists exceptions, such as where 24-hour staffing is required.

The night-work limit. GOV.UK says the night period is 11pm to 6am unless the worker and employer agree a different night period, and that staff who regularly work at least 3 hours in it are night workers. The key line is: "Night workers must not work more than an average of 8 hours in a 24-hour period." The average is usually calculated over 17 weeks, up to 52 weeks if agreed. "Regular overtime is included in the average, but not occasional overtime." And "Workers cannot opt out of the limit." Employers must keep records of night workers' hours.

So why is a 12-hour night shift lawful on this pattern? Because the limit is on the average, not on each shift. On the 42-hour pattern the simple average is 42 / 7 = 6 hours in each 24, below 8. The regulations set out their own method for working out the average, so ask your employer how it is calculated for your rota. A single 12-hour night does not break the limit by itself. What can break it is heavy regular overtime on top, which counts. Whether a particular rota complies depends on the reference period and any agreements, so that is a question for the employer, your contract and Acas.

Rest. GOV.UK says workers have the right to one uninterrupted 20-minute break if they work more than 6 hours, "11 hours rest between working days", and either an uninterrupted 24 hours without work each week or 48 hours each fortnight. On a 6am to 6pm pattern there are 12 hours between finishing and starting the next day, so the 11-hour rule is met. Four days off gives the weekly rest.

Compensatory rest. GOV.UK says workers "may be entitled" to compensatory rest if they do not have the right to specific rest breaks. Shift workers may qualify when they "cannot take daily or weekly rest breaks between ending one shift and starting another", and it can apply where "the job needs round-the-clock staffing". It matters on changeovers and if overtime eats into your rest.

How does pay work? Base, allowance, overtime

The pattern itself does not set pay, the contract does. Common elements are a basic salary, a shift allowance or premium, overtime at a set rate, and call-out pay. We do not quote a typical shift premium because we found no source for one. Ask for the figures in writing.

What we can source: the National Careers Service lists £27,000 starter and £48,000 experienced pay for an engineering maintenance technician, at 40 to 42 hours a week and "evenings / weekends / bank holidays on shifts" (read 28 October 2026). The ONS Annual Survey of Hours and Earnings 2026 provisional, Table 14.7a, shows full-time medians of £41,942 for metal working production and maintenance fitters, £40,717 for electricians and electrical fitters, and £44,785 for electrical service and maintenance mechanics. These are all-sector medians for the occupation, not shift-pattern figures.

We searched for live 4-on-4-off adverts on 28 October 2026, but the agency pages we tried to open returned "not found" and two government job pages were unavailable, so we quote no advert. Check the advert you are reading, note who posted it and when, and remember agency adverts sometimes quote on-target earnings that include overtime.

What are the pros and cons for maintenance engineers?

Pros: long blocks off, which many people use for family, study or travel; and fewer commutes.

Cons: 12-hour days are tiring in a demanding job; two or four nights in a row disrupt sleep; you may miss weekends and events that fall on shift days; and nights often have thinner cover, so you may work alone and make more calls on your own.

HSE's guide is balanced on this. HSG256 says 12-hour shifts are popular because they make the working week shorter and "may offer some advantages over 8-hour shifts in terms of sleep, health and well-being", but that "fatigue, especially towards the end of a long shift or during the night may reduce productivity and increase the risk of accidents". It adds that any advantage "is likely to be lost if workers take on overtime or second jobs".

Staying well on nights: what HSE advises

HSG256 (first published 2006, free to read on the HSE site) is guidance for employers, not law, but it is useful to know what a good rota looks like. It advises that:

• shifts should not be planned longer than 12 hours, including overtime;
• 12-hour night shifts should be limited to 2 to 3 consecutive nights, which makes the 16-day version with four nights in a row worth asking about;
• demanding, dangerous or safety-critical work should be avoided at night and towards the end of long shifts;
• where possible, rotation should be forward (days, then nights) rather than backward, and either very fast (every 2 to 3 days) or slow (every 3 to 4 weeks), avoiding weekly rotation;
• permanent night shifts should be avoided.

For personal habits, one useful talk is by Oxford circadian neuroscientist Professor Russell Foster on advice for shift workers. The video is a podcast clip, not medical advice; speak to your GP if nights affect your health.

What should you ask before you accept?

1. Is it the 8-day or the 16-day version, and how many nights in a row?
2. What are the shift start and end times, and how long is handover?
3. How is pay made up: basic, allowance, overtime, call-outs?
4. Is overtime regular or occasional, and is it voluntary?
5. How many engineers are on site at night, and who do you call?
6. How are holidays counted on a 12-hour pattern?
7. Does the company give a working-time or night-worker health check, and where are the hours records kept?

Where are these jobs, and where can you practise?

4-on-4-off patterns turn up in food and drink, distribution, packaging and process sites. Browse multi-skilled maintenance engineer roles, electrical maintenance engineer roles and the maintenance jobs page. For pay background, see the multi-skilled maintenance engineer salary page and our multi-skilled maintenance engineer guide.

Start free

The multi-skilled maintenance engineer job simulation is a free way to practise the work, with the first five days free. It is practice, not employment, and EDWartens does not place people in jobs. Use the jobs pages to see what employers are advertising, and read the GOV.UK night working hours page and the Acas working time page before you sign.