HGV Drivers’ Hours Calculator: Limits, Breaks and Weekly Rest

An HGV drivers hours calculator checks driving and working time against four driving limits: 4.5 hours before a 45 minute break, 9 hours a day, 56 hours a week and 90 hours over two weeks. A complete check also covers daily rest, weekly rest and the Working Time Directive, which caps total work as well as driving.

Whether it is called a driving hours calculator, a tacho calculator or an HGV driving hours calculator, it works from the activity record the tachograph makes. It shows how much driving time is left today and this week, when the next break is due, and whether total working time is inside the law. The answer is only as good as the modes the driver selects during the shift.

This guide sets out each limit, shows how to run the calculation by hand, and explains where drivers and transport managers most often go wrong. The same rules apply to LGV drivers, because LGV and HGV both describe goods vehicles over 3.5 tonnes.

The Driving Limits an HGV Drivers Hours Calculator Checks

Most HGVs in Great Britain follow the assimilated drivers’ hours rules, the version of EU Regulation 561/2006 that still applies in GB law. Those rules set the four driving limits below, and vehicles under the GB domestic rules follow different limits, covered later in this section.

These limits count only time at the wheel. Every other part of the shift falls into one of three other categories, and a drivers hours calculator needs each one recorded correctly.

Recording waiting time at a depot as rest is one of the most common mistakes. If the driver does not know how long the wait will be, it is other work; if the length is known, it is POA, and neither counts as a break. The Pocket Box guide to tacho symbols and their meanings shows which mode to select for each activity.

When the GB Domestic Rules Apply Instead

Some goods vehicle work falls outside the assimilated rules, mainly vehicles of 3.5 tonnes or less and certain exempt operations. Those drivers follow the GB domestic rules, which set a 10 hour daily driving limit and an 11 hour daily duty limit, with no weekly driving cap.

If a vehicle is in scope of the assimilated rules at any point in a day, those rules apply for the whole day. DVSA explains which rules cover each type of operation in its drivers’ hours guidance on GOV.UK.

When the EU Rules Apply

Drivers on journeys between Great Britain and the EU follow the EU version of Regulation 561/2006 for the whole journey. The daily, weekly and fortnightly limits are the same, so an EU drivers hours calculator gives the same driving answer. The differences sit in record keeping and enforcement, covered in the records section below.

How the 45 Minute Break Rule Works

After 4.5 hours of driving, a driver must take a break of at least 45 minutes before driving again. The break can be taken in one block or split into two parts.

A split break has a fixed order: at least 15 minutes first, then at least 30 minutes. Taking 30 minutes and then 15 does not count, and nor do two breaks of 20 and 25 minutes, even though both add up to 45. Once a valid break is complete, the 4.5 hour clock restarts.

A short stop does not count towards the break unless the tachograph is switched to the break mode. Most units move to other work automatically when the vehicle stops, so a 45 minute stop left on that mode is recorded as work and creates an infringement.

Worked Example of a Compliant Shift

The table follows a driver who starts at 06:00 and uses a split break. The right-hand column shows the running driving total that a calculator would track through the day.

The driver finishes with 8 hours 30 minutes of driving, inside the 9 hour daily limit. The split break was completed in the right order before 4.5 hours of driving had built up, so the afternoon driving starts a fresh 4.5 hour period.

Total working time is 9 hours 45 minutes: 8 hours 30 minutes of driving plus 1 hour 15 minutes of other work. The 45 minutes of breaks are not working time. This is the figure that counts towards the Working Time Directive totals covered below.

Weekly and Fortnightly Limits in Practice

The 56 hour weekly limit is easy to track on its own. The 90 hour limit is where most errors happen, because it rolls forward every week.

At any point, this week’s driving plus last week’s driving must not exceed 90 hours. If a driver does 50 hours in week one, week two is capped at 40 hours. In week three, week one drops out, so the cap becomes 90 hours minus whatever was driven in week two.

A driver who reaches the full 56 hours in one week can drive only 34 hours the next. A calculator that shows the remaining fortnightly allowance before the week starts lets the planner see that limit before the rota is set.

Driving Time and Rest Periods: Daily and Weekly Rest

Rest is calculated separately from breaks, and a full HGV drivers hours calculator tracks both. Daily rest resets the daily driving limit, while weekly rest resets the six day working pattern.

Daily Rest

A regular daily rest is at least 11 hours, taken within 24 hours of the end of the previous daily or weekly rest. It can be split into two periods, the first of at least 3 hours and the second of at least 9 hours, which makes a total of 12 hours. A reduced daily rest is at least 9 hours, and a driver may take no more than three reduced daily rests between any two weekly rests.

Weekly Rest and Compensation

A regular weekly rest is 45 hours; a reduced one is 24. In any two consecutive weeks, a driver must take either two regular weekly rests or one regular and one reduced rest. Each weekly rest must begin no later than the end of six 24 hour periods after the previous weekly rest ended.

Every reduced weekly rest creates a debt. The missing hours must be taken in one block before the end of the third week after the reduced rest, and attached to another rest of at least 9 hours.

A driver who takes 30 hours instead of 45 owes 15 hours, which might be added to a daily rest to make 26 hours in one go. Missed or miscalculated compensation is a common finding at roadside checks, because it is easy to forget once the following weeks are busy.

Working Time Directive and HGV Drivers

The Road Transport (Working Time) Regulations 2005, often called the Working Time Directive or WTD, sit on top of the drivers’ hours rules. Drivers’ hours govern driving; the WTD governs all work, including driving, other work and training. The Pocket Box guide to HGV working time directive breaks covers the WTD in full.

The main WTD limits for mobile workers are:

• an average of no more than 48 hours of work a week, usually measured over a 17 week reference period (extendable to 26 weeks by agreement)
• no more than 60 hours of work in any single week
• no more than 6 hours of work without a break, with at least 30 minutes of breaks when working 6 to 9 hours, and 45 minutes when working more than 9 hours
• no more than 10 hours of work in any 24 hour period in which night work is done (midnight to 04:00 for goods vehicles), unless a workforce agreement allows otherwise

Mobile workers cannot opt out of the 48 hour average, unlike many other workers in the UK. The limit applies to every driver covered by the 2005 Regulations, whatever their contract says.

The gap between the two sets of rules is easy to miss. A driver who drives 50 hours in a week and spends 2 hours a day on checks and loading over five days reaches 60 hours of work. The driving is within the 56 hour limit, but the WTD weekly maximum has been reached, and any further work that week, driving or not, is a breach. A calculator that tracks only driving would not show it.

How to Calculate Your HGV Hours Manually

Working out hours by hand lets a driver check a calculator’s output and understand why an infringement has been flagged. It needs the day’s activity record from the tachograph printout or chart.

1. Note the time the duty period started.
2. List each activity in order, with start and end times: driving, other work, POA and breaks.
3. Add up the driving time and check it against 9 hours, or 10 if this is one of the two extended days that week.
4. Check that a valid 45 minute break, or a 15 then 30 minute split, came before 4.5 hours of driving.
5. Add the other work to the driving to get working time, and check it against the WTD weekly totals.
6. Check the rest that follows: at least 11 hours, or 9 if a reduced daily rest is still available.

The manual method works well for one driver planning one shift. It becomes impractical once a transport manager is checking the weekly and fortnightly totals for a whole fleet.

Avoiding Common Calculation Mistakes

Most infringements found at roadside checks come from a handful of recording errors rather than deliberate overruns. An HGV drivers hours calculator only flags them if the underlying record is right, so each needs checking at source.

• A stop counts as a break only if the break mode is selected, so a 45 minute stop recorded as other work leaves the driver in breach once driving resumes.
• A split break taken as 30 minutes followed by 15 minutes fails the rule, even though the total is 45 minutes.
• Time spent waiting at a depot is other work or POA, never rest, and logging it as rest makes the daily rest look longer than it was.
• Reduced weekly rest debts are easy to lose track of over three weeks, particularly when a driver changes vehicles or depots.
• Checks, loading and paperwork do not touch the driving limits, but they count in full towards the WTD totals.

Records Drivers Must Show at a Roadside Check

Drivers on journeys within the UK must be able to show records for the current day and the previous 28 days. Since 31 December 2024, drivers of HGVs over 3.5 tonnes on international journeys between the UK and the EU must show the current day and the previous 56 days, including any manual records and analogue charts.

Operators must download each driver card at least every 28 days and each vehicle unit at least every 90 days. The Pocket Box guide to the digital tachograph card explains how the card stores this data and what to do if one is lost.

Since 5 March 2018, DVSA traffic examiners have been able to issue fixed penalties of up to £300 each for drivers’ hours offences committed in the previous 28 days. They can issue penalties for up to five offences in one check, so a single stop can cost a driver £1,500.

Serious or repeated offences can lead to prosecution and a public inquiry before a Traffic Commissioner. The Pocket Box guide to drivers’ hours regulations in the UK covers enforcement in more detail.

Choosing Between a Mobile App and Fleet Software

The right type of HGV drivers hours calculator depends on how many drivers need tracking. A single driver can plan with a simple tool, but an operator needs records that can be reviewed later.

Whatever the tool, an HGV drivers hours calculator is a planning aid. DVSA examiners check the tachograph record itself, and a calculator result carries no weight as evidence.

Managing this across a fleet

A calculator answers the question for one driver and one shift. A transport manager with 15 or 30 drivers needs to know, before next week’s rota is set, who is close to the 56 hour weekly limit, who has only 34 hours left in the fortnight, and who still owes weekly rest compensation. That depends on tachograph data downloaded on time and on journey plans that reflect how long routes really take.

Pocket Box Vehicle Tracking records every journey and stop, so planners can base shift lengths on real journey times and spot a long stop where no break was recorded. Pocket Box Fleet handles the rest of the driver file, including digital walkaround checks through the Pocket Box Driver App, defect reports, licence checks and inspection reminders. The tachograph remains the legal record of drivers’ hours. For a checklist of the records operators are expected to keep, download the free UK Fleet Compliance Guide.

Frequently Asked Questions