From raw data to results
How TruckerMaster performs its calculations
Updated on 8 August 2026 · by Yann, working truck driver
Every result must be traceable to a piece of data, a rule, a period and a calculation method the driver can understand.
The data used
TruckerMaster invents no data. It reads what you give it, and nothing else. Here are the only sources it can work with, and what each one feeds.
| Source | Where it comes from | What it feeds |
|---|---|---|
| Driver card file | USB smart card reader, or import of a .DDD / .C1B file you already have | Daily calendar, pay audit, offence detection, evidence file |
| Payslip | Photo analysed on the device, or manual entry of the amounts | Pay audit only |
| Live ITS data | Bluetooth link with a 2nd-generation smart tachograph, after authorisation given on the vehicle unit | Real-time driving-hours cockpit |
| Your contract settings | Entered by you: hourly rate, coefficient, category, thresholds, premiums, allowance scales | Pay audit, comparison with the legal minimum |
| Regulatory rules | Built into the app, sourced and dated (see below) | Time analysis, offence detection, Saute-Mouton assistant |
There is no company account, no company card, no access to a fleet server. TruckerMaster cannot go and fetch data you have not given it.
How the pay audit is built
The audit compares two things: what your card recorded, and what your payslip paid. Here is the full chain.
- Reading the activities — driving, other work, availability, rest, exactly as recorded on the card.
- Rebuilding the days — each activity is placed back in its duty day, with its start and end of duty.
- Identifying the periods — duty span, service time, breaks, night work, Saturdays and Sundays.
- Analysing the payslip — the paid lines are extracted from the photo, or entered by hand.
- Checking by you — every value stays editable; the app flags those that are clearly implausible.
- Applying your settings — rates, coefficient, thresholds and premiums from your contract, not from a standard one.
- Calculating hours and premiums — normal hours, equivalence hours, overtime, night, weekend, allowances.
- Comparing with the amounts paid — line by line, never as a lump sum.
- Calculating the gaps — in hours, in days and in euros, both ways: what is missing as well as what was overpaid.
- Generating the report — detailed summary and a letter requesting adjustment.
⚠ A piece of data recognised automatically must be able to be checked and corrected before it is used in a report. That is the basic rule of the audit: image reading makes mistakes, and a wrong figure at the start produces a wrong gap at the end.
Six kinds of data, not to be confused
Read data
Decoded from the card file. This is the tachograph recording, the most reliable source you have.
Recognised data
Extracted from the photo of the payslip. To be checked every time: this is the most fallible step of the chain.
Entered data
What you type in yourself: rates, coefficient, scales. The app does not guess them.
Calculated data
Produced by the engine from the three previous kinds, according to explicit rules.
Assumptions
An item missing from an entered payslip is counted as paid zero, not as unknown. That is a methodological choice, shown as such.
Results
Quantified gaps, to be read as a basis for discussion — not as a decision.
Outlier values are removed from the total and flagged: no hourly item can exceed 320 hours paid in a month, no day counter can exceed 31. An image reading that produces 2 120 equivalence hours is an error, not a claim.
How times and offences are analysed
Two analyses coexist, and they do not serve the same purpose.
From the card
Analysis of the past. The recorded days are replayed and checked against the rules: daily and weekly driving, breaks, rest, overruns. What comes out are offences already committed.
From the live cockpit
Analysis of the present. The counters read from the vehicle unit are used to anticipate: time remaining, next break, current risk. What comes out are alerts, not findings.
In both cases, the type-approved tachograph remains the recording reference. TruckerMaster reads and interprets; it never writes into the vehicle unit, and it is up to the driver to select their activity.
The texts and scales used
The rules applied by the engine come from specific texts. Here they are, with their date and the date on which they were checked against the source.
-
Règlement (CE) n° 561/2006 — driving times, breaks and rest
EUR-Lex, European Union · text of 15 March 2006, consolidated version · checked on 8 August 2026
-
Règlement (UE) n° 1266/2009 — the one-minute recording rule
EUR-Lex, European Union · text of 16 December 2009 · checked on 8 August 2026 · basis of the Saute-Mouton assistant
-
Convention collective nationale des transports routiers (CCNTR, IDCC 16)
Légifrance, French Ministry of Justice · checked on 8 August 2026 · pay scales, coefficients and equivalence regime
-
Code du travail — working time and overtime
Légifrance, French Ministry of Justice · checked on 8 August 2026 · premiums of 25 % and 50 %
For country-by-country traffic restrictions, the sources are cited on each page: see the heavy goods vehicle regulations in Europe.
How the calculations are tested
A calculation engine that changes without a safety net ends up getting things wrong in silence. TruckerMaster's engine is covered by an automated test suite, replayed on every change.
205
automated tests across the whole project
14
covering the pay engine specifically
23
languages, whose coverage is itself tested
What these tests actually check:
- The decoding of the card file and the rebuilding of the duty spans.
- The driving, break and rest rules, including across midnight and at clock changes.
- The building of the comparison lines between card and payslip, and the calculation of the gaps.
- The rejection of outlier values coming from image reading.
- The presence of every translation key in the 23 languages.
These figures are collected automatically from the project at every release, and are only published if all tests pass. A number of tests is not a legal validation: it says the engine does what is expected of it, not that your employer owes you anything.
What TruckerMaster can and cannot guarantee
This section is deliberately as visible as the previous ones. A tool that does not show its limits is not a trustworthy tool.
Payslip quality varies
Faint printing, cramped columns, a comma read as a full stop: image reading makes mistakes. It must be reread.
Your contract prevails
Company agreement, custom and practice, amendment: your situation may be more favourable than the scale you entered, or simply different.
Rules change
Texts and scales evolve. The check date is displayed; beyond it, check the source.
Countries differ
Labour law remains national. The pay engine is built on the French framework; other countries are audited by entering your own values.
Compatibility is not universal
Reader, phone, vehicle unit: not everything works everywhere. Check the requirements.
The source itself can be wrong
An activity wrongly selected on the vehicle unit produces an inaccurate recording — which the app will take exactly as it is.
What the app does not do: it does not guarantee the absence of error, it does not guarantee the absence of offence, and a generated report is not automatically admissible or accepted. For a step that matters — a claim, an inspection, legal proceedings — have your file reviewed by a trade union, a union advocate or a qualified professional.
The calculations run on your device, from your files. To know exactly which function touches which data: see where your data is processed.
Check the data before drawing a conclusion
TruckerMaster makes every calculation readable so the driver can understand, check and export their result.
Download free on Android