System for determining a tread depth D of a vehicle tyre, having: a signal reception interface, a first processor unit, and a memory unit, wherein the signal reception interface is designed to receive a measurement signal M from an acceleration sensor of the vehicle tyre, the measurement signal M at least indirectly representing a radial acceleration A acting on a tread pattern of a tread of the vehicle tyre, wherein the memory unit stores a reference tread depth E of the tyre tread pattern, wherein the first processor unit is configured to take the measurement signal M as a basis for determining a process signal that at least indirectly represents an acceleration gradient B of the radial acceleration A acting on the tyre tread pattern of the tread of the vehicle tyre or of the radial acceleration A acting on an inner liner of the vehicle tyre, wherein the first processor unit is configured to determine a revolution time U of the vehicle tyre on the basis of the measurement signal M and/or the process signal, wherein the first processor unit is configured to take the process signal as a basis for determining a first parameter P 1 that at least indirectly represents a maximum acceleration gradient B max during the revolution time U, a minimum acceleration gradient B min during the revolution time U or a mean value from the maximum and minimum acceleration gradients B max, B min during the revolution time U, wherein the first processor unit is configured to take the process signal as a basis for determining a second parameter P 2 that at least indirectly represents either an interval of time Z between the maximum and minimum acceleration gradients B max, B min during the revolution time U or a ratio between the interval of time Z and the revolution time U, and wherein the first processor unit or an optional second processor unit of the system is configured to ascertain the tread depth D of the tyre tread pattern of the tread of the vehicle tyre on the basis of the reference tread pattern E, the first parameter P 1 and the second parameter P 2, characterized in that a three-dimensional family of characteristic curves is stored by the memory unit or by an optional second memory unit, wherein the family of characteristic curves represents possible tread depths D on the basis of possible reference tread depths E, possible magnitudes for the first parameter P 1 and possible magnitudes for the second parameter P 2, and wherein the processor unit 8, 18 provided for ascertaining the reference tread depth D is configured to ascertain the reference tread depth D of the tread pattern of the tread of the vehicle tyre by means of the family of characteristic curves and on the basis of the stored reference tread depth E, the determined first parameter P 1 and the determined second parameter P 2. a signal reception interface, a first processor unit, and a memory unit, wherein the signal reception interface is designed to receive a measurement signal M from an acceleration sensor of the vehicle tyre, the measurement signal M at least indirectly representing a radial acceleration A acting on a tread pattern of a tread of the vehicle tyre, wherein the memory unit stores a reference tread depth E of the tyre tread pattern, wherein the first processor unit is configured to take the measurement signal M as a basis for determining a process signal that at least indirectly represents an acceleration gradient B of the radial acceleration A acting on the tyre tread pattern of the tread of the vehicle tyre or of the radial acceleration A acting on an inner liner of the vehicle tyre, wherein the first processor unit is configured to determine a revolution time U of the vehicle tyre on the basis of the measurement signal M and/or the process signal, wherein the first processor unit is configured to take the process signal as a basis for determining a first parameter P 1 that at least indirectly represents a maximum acceleration gradient B max during the revolution time U, a minimum acceleration gradient B min during the revolution time U or a mean value from the maximum and minimum acceleration gradients B max, B min during the revolution time U, wherein the first processor unit is configured to take the process signal as a basis for determining a second parameter P 2 that at least indirectly represents either an interval of time Z between the maximum and minimum acceleration gradients B max, B min during the revolution time U or a ratio between the interval of time Z and the revolution time U, and wherein the first processor unit or an optional second processor unit of the system is configured to ascertain the tread depth D of the tyre tread pattern of the tread of the vehicle tyre on the basis of the reference tread pattern E, the first parameter P 1 and the second parameter P 2, characterized in that a three-dimensional family of characteristic curves is stored by the memory unit or by an optional second memory unit, wherein the family of characteristic curves represents possible tread depths D on the basis of possible reference tread depths E, possible magnitudes for the first parameter P 1 and possible magnitudes for the second parameter P 2, and wherein the processor unit 8, 18 provided for ascertaining the reference tread depth D is configured to ascertain the reference tread depth D of the tread pattern of the tread of the vehicle tyre by means of the family of characteristic curves and on the basis of the stored reference tread depth E, the determined first parameter P 1 and the determined second parameter P 2.