Definition of giftedness

The intelligence quotient is not an absolute value, but a percentile rank and therefore a comparative value. Assessment and conversion are carried out using the Gaussian normal distribution. 

In practice, this means: 

In an IQ test, you are presented with tasks and it is determined how well you solve these tasks compared to other people of the same age. In Germany, you are considered gifted if you have solved these tasks better than 97.8% of the population, i.e. 2.2% of the population is defined as gifted. This corresponds to an IQ of ≥ 130. 
In Germany, from a percentile rank of 99.9 one is considered maximum gifted. This means that only one in a thousand people can solve the tasks as well as this person, corresponding to an IQ value of 145. The cut-off value for giftedness is arbitrarily defined. In France, for example, the upper 5% are considered gifted.