You do not need to measure the exact amount of your activity; although, it does help to keep you motivated. With that in mind, do not worry about going overboard with the feeling that you must have the exact measure of a mile or your steps.
We all have our own stride length for many reasons; so, please, use this tip as a ball park figure for comparison in your log. Remember, it is approximately 2000 steps in a mile, not exactly 2000 steps.
Now, if you want to get more exercise while doing those steps, go out into the mud as I did. Boy, that wet clay sure does get heavy and bog me down. The photo shows the mud dry and shaken off from yesterday when I had to divert puddles of water away from our building. No worries, I left enough room and water for the little tree frogs and tadpoles to mature. I have all kinds of company everywhere I go, yay.