Significantly older
The year of Gimli's birth is given in Appendix A, in the family tree for the Line of Durin, as 2879 of the Third Age (click to embiggen):
Appendix B gives the date of the Council of Elrond as October 25, 3018.
So Gimli is actually almost 140 when we first meet him, and is certainly that age by the end of the trilogy.