Method for determining a profile depth of a tyre profile, having at least the following steps: a) detecting an acceleration (a r, a t) of a measurement point on a tyre inner side of a vehicle tyre, wherein a deviation, caused by contact of the vehicle tyre with a roadway, of the acceleration (a r, a t) of the measurement point within an observation window is detected, b) deriving at least one analytical characteristic variable (S 1, S 2, a t,1, a t,2, B) which is characteristic of the profile of the detected acceleration (a r, a t), wherein the at least one analytical characteristic variable (S 1, S 2, a t,1, a t,2, B) characterizes the non-periodic profile of the detected acceleration (a r, a t) within one tyre rotation, c) determining the profile depth in a manner dependent on the at least one analytical characteristic variable (S 1, S 2, a t,1, a t,2, B), wherein a calibration curve (10a, 10b, 10c, 10d, 10e) yields the dependency between the analytical characteristic variable (S 1, S 2, a t,1, a t,2, B) and the profile depth, and the calibration curve (10a, 10b, 10c, 10d, 10e) assigns a profile depth to the derived analytical characteristic variable (S 1, S 2, a t,1, a t,2, B), characterized in that, for the determination of the profile depth, a calibration curve (10a, 10b, 10c, 10d, 10e) is used which runs within a linear tolerance band (F Ta, F Tb, F Tc, F Td, F Te), wherein the tolerance band (F Ta, F Tb, F Tc, F Td, F Te) runs with a deviation of less than 15% around a linear approximation to the calibration curve (10a, 10b, 10c, 10d, 10e), wherein a monotonous calibration curve (10a, 10b, 10c, 10d, 10e) is used which runs linearly, wherein the profile depth is determined from a multiplication of the at least one analytical characteristic variable (S 1, S 2, a t,1, a t,2, B) by a gradient (F a, F b, F c, F d, F e) of the calibration curve (10a, 10b, 10c, 10d, 10e) taking into consideration a tyre characteristic constant (C a, C b, C c, C d, C e). a) detecting an acceleration (a r, a t) of a measurement point on a tyre inner side of a vehicle tyre, wherein a deviation, caused by contact of the vehicle tyre with a roadway, of the acceleration (a r, a t) of the measurement point within an observation window is detected, b) deriving at least one analytical characteristic variable (S 1, S 2, a t,1, a t,2, B) which is characteristic of the profile of the detected acceleration (a r, a t), wherein the at least one analytical characteristic variable (S 1, S 2, a t,1, a t,2, B) characterizes the non-periodic profile of the detected acceleration (a r, a t) within one tyre rotation, c) determining the profile depth in a manner dependent on the at least one analytical characteristic variable (S 1, S 2, a t,1, a t,2, B), wherein a calibration curve (10a, 10b, 10c, 10d, 10e) yields the dependency between the analytical characteristic variable (S 1, S 2, a t,1, a t,2, B) and the profile depth, and the calibration curve (10a, 10b, 10c, 10d, 10e) assigns a profile depth to the derived analytical characteristic variable (S 1, S 2, a t,1, a t,2, B), characterized in that, for the determination of the profile depth, a calibration curve (10a, 10b, 10c, 10d, 10e) is used which runs within a linear tolerance band (F Ta, F Tb, F Tc, F Td, F Te), wherein the tolerance band (F Ta, F Tb, F Tc, F Td, F Te) runs with a deviation of less than 15% around a linear approximation to the calibration curve (10a, 10b, 10c, 10d, 10e), wherein a monotonous calibration curve (10a, 10b, 10c, 10d, 10e) is used which runs linearly, wherein the profile depth is determined from a multiplication of the at least one analytical characteristic variable (S 1, S 2, a t,1, a t,2, B) by a gradient (F a, F b, F c, F d, F e) of the calibration curve (10a, 10b, 10c, 10d, 10e) taking into consideration a tyre characteristic constant (C a, C b, C c, C d, C e). for the determination of the profile depth, a calibration curve (10a, 10b, 10c, 10d, 10e) is used which runs within a linear tolerance band (F Ta, F Tb, F Tc, F Td, F Te), wherein the tolerance band (F Ta, F Tb, F Tc, F Td, F Te) runs with a deviation of less than 15% around a linear approximation to the calibration curve (10a, 10b, 10c, 10d, 10e), wherein a monotonous calibration curve (10a, 10b, 10c, 10d, 10e) is used which runs linearly, wherein the profile depth is determined from a multiplication of the at least one analytical characteristic variable (S 1, S 2, a t,1, a t,2, B) by a gradient (F a, F b, F c, F d, F e) of the calibration curve (10a, 10b, 10c, 10d, 10e) taking into consideration a tyre characteristic constant (C a, C b, C c, C d, C e).