Why the notice doesn't show the measured value
Drivers caught by a speed camera are often surprised: the photo says 76 km/h, but the hearing form says 73 km/h. This is not a mistake but the tolerance deduction. Every measuring device has a permitted margin of error, and it is always deducted in the driver's favour. Only the speed after the deduction — the chargeable speed — decides which band of the fine catalogue applies.
The rule: 3 km/h or 3%
For the usual fixed and mobile speed cameras: up to a reading of 100 km/h, 3 km/h is deducted. If the reading is above 100 km/h, 3% of the reading is deducted. Decimal places are dropped in your favour, so the result is rounded down to whole km/h.
A few examples: a reading of 76 km/h gives 73 km/h. A reading of 100 km/h gives 97 km/h. At 101 km/h, 3% is exactly 3.03 km/h, leaving 97.97 km/h, rounded down to 97 km/h. At 153 km/h the deduction is 4.59 km/h. That leaves 148.41 km/h, and the notice shows 148 km/h.
With other methods the deduction can be much larger. If speed is measured by following in a police car without a calibrated measuring system, courts apply larger safety margins. Our traffic fine calculator uses the standard rule of 3 km/h or 3%.
The expensive thresholds
Because the fine catalogue works in bands, a single km/h can cost a lot of money. In town with a 50 limit, the key thresholds are: from a reading of 74 km/h you are 21 km/h over after the deduction. That costs €115 and one point instead of €70. From a reading of 84 km/h it is 31 km/h over. That means €260, two points and a one-month driving ban.
Out of town with a 100 limit, the percentage rule applies above 100 km/h. From a reading of 125 km/h, 121 km/h remain after the deduction — 21 km/h over, so €100 and one point. Out of town, the driving ban starts at 41 km/h over. That needs 141 km/h left after the deduction, which is the case from a reading of 146 km/h. At 145 km/h only 140 km/h remain: €200 and one point, but no driving ban.
What to check on your notice
Compare the measured value, the tolerance deduction and the chargeable speed. Also check whether the offence was classed as in town or out of town. The town sign is what counts, not the buildings along the road. And check that the correct speed limit was applied. If something doesn't match, it is worth asking the fine office or getting legal advice. An objection must be filed within two weeks of delivery.
Conclusion
The tolerance deduction is clearly regulated and easy to recalculate: 3 km/h up to 100 km/h, 3% above that, then round down. If you know your reading, the traffic fine calculator instantly shows which band applies, plus points, driving ban and total cost. For more on points, probation and limitation periods, see the guide to Germany's fine catalogue 2026.