On average, every week, you will spend 105 minutes on the toilet if you are a man, and 85 minutes if you are a woman. That is quite a bit of time, and it means that your toilet will have a lot of wear and tear.
If you have an older toilet, it could use as much as 7 gallons of water each time you flush, and therefore, you can just imagine how much water that adds up to over time. If there are leaks due to the toilet being old, as well, this can add a substantial amount of water wasted. Even if you are not paying for water usage where you live, it should still be of concern to you since fresh water sources are being depleted.
If your toilet bowl or tank is cracked, this is a definitive sign that it is time to invest in a new toilet. Having contaminated water leak out on your floor could lead to extensive cleanup work.
You should also make sure that there is nothing loose on your toilet. The tank should be firmly attached to the bowl and the toilet to the floor.