The average stride length for men is 0.78 m and 0.7 m for women.
An approximation to your personal walking stride is multiplying your height with 0.415 (or 0.413 for women). For example:
1.82 (your height) x 0.415 = 0.76 m
Another way of finding out is simply taking ten steps, measuring the length and dividing that by 10.